In a structure including a voltage control circuit 1 for changing a voltage control signal 14 to control an oscillation amplitude of a transistor Q1 for oscillation, thereby stabilizing a voltage of a secondary output 13, there are provided a load suppressing circuit 5 for restricting a lower limit of a load impedance of a secondary coil L2 to prevent the oscillation of the transistor Q1 for oscillation from being stopped when the secondary output 13 is short-circuited, and an intermittent control circuit 2 for repeating an operation for reducing a voltage of the voltage control signal 14 to stop the oscillation when detecting a short circuit of a load and for raising the voltage of the voltage control signal 14 to restart the oscillation after stopping the oscillation.

1. Field of the Invention
The present invention relates to a toner system printer for carrying out printing by using a toner such as a laser system printer or a copying machine, and more particularly to a high voltage generating circuit for generating a high voltage to be required for toner system printing.
2. Description of the Related Art
JP-A-63-87173 has disclosed the conventional art in which a switching operation is changed into an intermittent operation to prevent the breakdown of an oscillating element when an output is short-circuited in a switching power source. In this technique, a resistor for detecting a current is inserted in a current path of an emitter of a switching transistor. When a voltage of the emitter exceeds a predetermined voltage, a current of the switching transistor is controlled to be a constant current. Moreover, a comparator for detecting that a load is short-circuited is provided. When a short circuit is caused, the switching operation of the switching transistor is stopped by the comparator. Furthermore, when a charging period of a capacitor for soft start is passed after the switching operation is stopped, the switching is restarted. In other words, when the load is short-circuited, the switching transistor carries out intermittent oscillation. Therefore, the switching transistor is prevented from being broken when the load is short-circuited (which is a first conventional art).
Moreover, JP-A-9-9616 has disclosed a technique. In this technique, when the short circuit of an output is detected, constant current charging for a capacitor is started. When a terminal voltage of the capacitor exceeds a first voltage, an internal bias source is turned OFF, thereby stopping the driving operation of a switching transistor. Then, when the terminal voltage of the capacitor is raised to be a second voltage which is higher than the first voltage, the capacitor is discharged to have an initial voltage, thereby restarting the driving operation of the switching transistor. In other words, when a load is short-circuited, the switching transistor is intermittently driven. Therefore, it is possible to prevent the switching transistor from being broken when the load is short-circuited (which is a second conventional art).
In a method in which a switching element is brought into a saturation state when it is turned ON as in the switching method according to the technique described above, large output power can cause efficient conversion to be carried out. However, in the case in which slight output power is enough as in a high voltage generating circuit for a toner system printer, a conversion efficiency is deteriorated and an unstable operation is caused. For this reason, the high voltage generating circuit for a toner system printer employs such a structure that a transistor for oscillation which is connected to a primary coil is always carries out self-oscillation in a non-saturation region and an amplitude of oscillation is controlled to stabilize an output voltage. In other words, there has been employed a structure in which an output voltage is stabilized by a method different from the first conventional art and the second conventional art.
FIG. 7 shows the structure described above, that is, a conventional art of a high voltage generating circuit for stabilizing an output voltage by controlling an amplitude of oscillation of a transistor for oscillation. More specifically, a transistor for oscillation Q1 (which will be hereinafter referred to as a transistor Q1) has a collector connected to a primary coil L1 and a base connected to one of terminals of an auxiliary coil L3. Moreover, an output of an OP amplifier 3 for generating a voltage control signal based on a voltage of a secondary output is led to the other terminal of the auxiliary coil L3. For this reason, the transistor Q1 increases an amplitude of oscillation when a voltage of the voltage control signal sent from the OP amplifier 3 is raised, and reduces the amplitude of the oscillation when the voltage of the voltage control signal is dropped. On the other hand, the OP amplifier 3 reduces the voltage of the voltage control signal when the voltage of the secondary output is raised to be higher than a set value, and raises the voltage of the voltage control signal when the voltage of the secondary output is reduced to be lower than the set value. Therefore, the voltage of the secondary output is stabilized to be a voltage set based on a voltage setting signal 22 (the reference numeral 21 denotes a path for applying a reference voltage to set an operating point of the OP amplifier 3).
In the structure described above, that is, such a structure that the voltage of the secondary output is stabilized by controlling the amplitude of the oscillation, the transistor Q1 stops the oscillation even if the oscillation is not externally stopped in respect of the relationship in which a load is too increased if an output is short-circuited. On the otherhand, in the case in which the oscillation of the transistor Q1 is stopped, the voltage of the output (voltage control signal) of the OP amplifier 3 is raised so that a base current of the transistor Q1 is increased. Therefore, a collector current is increased. More specifically, when the transistor Q1 is brought into an oscillation stop state, a calorific value becomes greater than that in the oscillation state so that an element is broken more easily. For this reason, the methods according to the first and second conventional arts (the structure in which a switching element is brought into a saturation state during turnxe2x80x94on) cannot be used as a method for carrying out protection when an output is short-circuited. Therefore, another method is used to protect the transistor Q1.
More specifically, when the output is short-circuited, the voltage of the voltage control signal sent from the OP amplifier 3 is raised. Therefore, there has been employed such a structure that a resistor R21 is inserted between the output terminal of the OP amplifier 3 and the other terminal of the auxiliary coil L3 and a clamp circuit comprising diodes D5 and D6 is connected between the resistor R21 and the auxiliary coil L3. Accordingly, the voltage of the other terminal of the auxiliary coil L3 is controlled to be approximately 1.3 V also when the output voltage of the OP amplifier 3 is raised. As a result, an increase in the base current of the transistor Q1 is restricted and an increase in the collector current is suppressed. Consequently, the transistor Q1 can be protected from breakdown (which is a third conventional art).
Moreover, FIG. 8 shows a structure in which a different method from the third conventional art is employed for protecting the transistor Q1. More specifically, a portion comprising the resistor R21 and the diodes D5 and D6 in FIG. 7 is replaced by a resistor R22 and a Zener diode D7 (other portions are identical to those of the structure shown in FIG. 7). In such a structure, accordingly, the voltage of the other terminal of the auxiliary coil L3 is shifted to the lower side by a Zener voltage of the Zener diode D7 with respect to the output voltage of the OP amplifier 3. Therefore, the voltage of the other terminal of the auxiliary coil L3 is controlled to be low also when the output voltage of the OP amplifier 3 is raised. As a result, an increase in the base current of the transistor Q1 is restricted and an increase in the collector current is limited. Consequently, the transistor Q1 can be protected from breakdown (which is a fourth conventional art).
For the secondary output, moreover, there has been proposed a structure in which a resistor R31 is inserted in a current path of a secondary output as shown in FIG. 9A. Alternatively, there has been proposed a structure in which a resistor R32 is inserted in the ground level side to detect a current value of the secondary output as shown in FIG. 9B. Moreover, there has been proposed a structure in which both a resistor R33 and a resistor R34 are inserted as shown in FIG. 9C.
However, the resistors R31 and R33 shown in FIGS. 9A and 9C are elements for controlling a maximum value of a discharge current of a capacitor C4 when a secondary output is short-circuited, there by preventing the capacitor C4 from being deteriorated. Moreover, the resistors R32 and R34 are elements for detecting the current oft the secondary output. Accordingly, the values of the resistors R31 to R34 are set to be comparatively small. As a result, when the secondary output is short-circuited, the load of the secondary coil L2 is too increased so that the oscillation of the transistor Q1 is stopped. When the oscillation is stopped, the collector current of the transistor Q1 is increased even if the third conventional art or the fourth conventional art is used. At this time, it is hard to reduce an increase in the current of the collector. For this reason, when the output is short-circuited, the calorific value of the transistor Q1 is increased. Accordingly, it is necessary to attach a radiator to the transistor Q1 or to set the transistor Q1 to be a large-sized element having a great allowable heat loss in order to prevent the thermal breakdown of the transistor Q1 during the short circuit of the output. Consequently, the cost of parts is increased.
Furthermore, also in the case in which the radiator is attached to the transistor Q1 or the transistor Q1 is set to be a large-sized element having a great allowable heat loss, the following problem arises. More specifically, it is dangerous to increase the length of a path for a high voltage sent from a high voltage generating circuit. Therefore, the high voltage generating circuit is provided in the vicinity of a toner system printing section having a photosensitive drum. Accordingly, when the secondary output is short-circuited so that the calorific value of the high voltage generating circuit is increased, an environmental temperature of the toner system printing section is raised. For this reason, the temperature of rollers of the photosensitive drum is raised so that the performance of the rollers is deteriorated. As a result, it is hard to uniformly charge the surfaces of the rollers. Consequently, printing performance is deteriorated.
The invention has been made to solve the problems and has an object to provide a high voltage generating circuit for a toner system printer which can restrict a lower limit of a load impedance of a secondary coil to prevent the oscillation of a transistor for oscillation from being stopped during a short circuit of a secondary output and can carry out intermittent oscillation to suppress an increase in the heat generation of the transistor for oscillation during the short circuit of the output, thereby preventing the performance of a toner system printing section from being deteriorated due to a rise in a temperature.
Another object of the invention is to provide a high voltage generating circuit for a toner system printer which can suppress an increase in the number of elements also during intermittent oscillation by using a circuit for restricting a lower limit of a load impedance as a circuit for detecting a short circuit of an output.
Still another object of the invention is to provide a high voltage generating circuit for a toner system printer which can suppress an increase in the number of elements also during intermittent oscillation by using a capacitor for changing a PWM signal into a direct current as a capacitor for delaying the restart of oscillation in the intermittent oscillation.
Yet still another object of the invention is to provide a high voltage generating circuit for a toner system printer which can optionally delay a period required for restarting the oscillation in the intermittent oscillation without causing an increase in a time constant of a circuit for changing a PWM signal into a direct current.
Yet still another object of the invention is to provide a high voltage generating circuit for a toner system printer which can cause the oscillation in the intermittent oscillation to sharply rise without an increase in the number of elements.
In order to solve the problem, the present invention provides a high voltage generating circuit for a toner system printer comprising a transformer having at least a primary coil, a secondary coil and an auxiliary coil wound thereon, a transistor for oscillation having a collector connected to the primary coil and a base connected to a first terminal of the auxiliary coil and serving to carry out self-oscillation, and a voltage control circuit for sending, to a second terminal of the auxiliary coil, a voltage control signal generated based on a voltage detection signal indicative of a voltage of a secondary output, wherein the voltage control circuit stabilizes the voltage of the secondary output by controlling an oscillation amplitude of the transistor for oscillation in response to the voltage control signal, and the secondary output is led to a high voltage applying portion of a toner system printing section, the high voltage generating circuit further comprising a load suppressing circuit inserted in a current path of the secondary coil and serving to restrict a lower limit of a load impedance of the secondary coil, thereby preventing the oscillation of the transistor for oscillation from being stopped when the secondary output is short-circuited, and an intermittent control circuit for repeating an operation for reducing a voltage of the voltage control signal to stop the oscillation of the transistor for oscillation when detecting a short circuit of a load, and for raising the voltage of the voltage control signal to restart the oscillation of the transistor for oscillation after stopping the oscillation of the transistor for oscillation.
More specifically, the load suppressing circuit prevents the transistor for oscillation from stopping the oscillation also when the secondary output is short-circuited. Accordingly, also in the case in which the secondary output is short-circuited, the transistor for oscillation carries out the oscillation when the intermittent control circuit is to raise the voltage of the voltage control signal. Moreover, when the intermittent control circuit is to reduce the voltage of the voltage control signal, the transistor for oscillation stops the oscillation. Consequently, also when the secondary output is short-circuited, the transistor for oscillation carries out the intermittent oscillation. Therefore, the heat generation of the transistor for oscillation can be suppressed.
In addition to the structure described above, moreover, the load suppressing circuit is a voltage dividing circuit inserted between a ground level side path of a rectifying and smoothing circuit for generating the secondary output having a negative voltage by rectifying and smoothing an output of the secondary coil and a ground level, and the intermittent control circuit detects the short circuit of the secondary output based on a divided voltage sent from the voltage dividing circuit.
More specifically, the load suppressing circuit also serves as a circuit for detecting the short circuit of the secondary output. Therefore, it is not necessary to separately provide a circuit for detecting the short circuit of the secondary output.
In addition to the structure described above, furthermore, there is provided a filter circuit including a resistor for a filter which has one of terminals connected to a signal source of a PWM signal and a capacitor for a filter which is connected between the other terminal of the resistor for a filter and the ground level and serving to change the PWM signal into a direct current, the voltage control circuit changing a level of the voltage control signal based on a voltage setting signal to be an output of the filter circuit and the voltage detection signal, thereby stabilizing the voltage of the secondary output into a voltage corresponding to the voltage setting signal, wherein the intermittent control circuit is a switch circuit for closing a connection between the output of the filter circuit and the ground level when detecting the short circuit of the secondary output, and a rise in a voltage of the output of the filter circuit which is caused when the connection of the switch circuit is opened is delayed by the capacitor for a filter, thereby delaying the restart of the oscillation in the intermittent oscillation.
More specifically, the capacitor for a filter serves as an element for delaying the restart of intermittence in the intermittent oscillation and an element to be the filter for changing a PWM signal into a direct current.
In addition to the structure described above, moreover, the intermittent control circuit includes a diode having an anode connected to the output of the filter circuit and a cathode connected to the switch circuit, and a capacitor for delay which is connected to the cathode of the diode, wherein the capacitor for delay is discharged when the connection of the switch circuit is closed.
More specifically, when the connection of the switch circuit is changed from a closed state to an open state, the capacitor for delay which is set in a discharge state is connected through the diode in parallel with the output of the filter circuit. Moreover, in the case in which the capacitor for delay is not set in the discharge state, the capacitor for delay is separated from the output of the filter circuit by the diode.
In addition to the structure described above, furthermore, the capacitor for delay is connected between an output point for a divided voltage of the voltage dividing circuit and the cathode of the diode.
More specifically, when the voltage between the terminals of the capacitor for delay is raised so that the oscillation is restarted and the divided voltage is raised, the voltage of the terminal on the diode side in the capacitor for delay is raised. Accordingly, the capacitor for delay is separated from the filter circuit through the diode. Consequently, the rise in the output voltage of the filter circuit is only delayed by the capacitor for a filter. Therefore, when the oscillation is restarted, the output voltage of the filter circuit is rapidly raised.

High voltage generating circuit for a toner system printer


A photosensitive transfer material is described, comprising a temporary support having formed thereon in sequence a thermoplastic resin layer, a separating layer having only slight permeability to oxygen, and a photosensitive resin layer, wherein the adhesion between the thermoplastic resin layer and the separating layer is weakest. The photosensitive transfer material is useful, for example, for an image-forming process.

An image-forming material for transferring the photosensitive resin layer thereof onto a substrate is known and disclosed in JP-B-56-40824 (corresponding U.S. Pat. No. 3,884,693) (the term "JP-B" as used herein means an "examined published Japanese patent application"). The image-forming material is used for making printed circuits, intaglio printing plates, relief printing plates, name plates, multicolor proofs, offset printing plates, screen printing stencils, etc.
The transfer material is composed of a temporary support, a separating layer, and a photopolymerizing layer. The photopolymerizing layer of the transfer material is laminated onto a substrate, then the temporary support only is separated therefrom, the photopolymerizing layer is imagewise exposed through the separating layer, and the photopolymerizing layer is developed to form images on the substrate. In this case, the separating layer allows for the imagewise exposure in air by intercepting oxygen, which is important since the thickness of the separating layer is very thin, as from about 0.5 .mu.m to 5 .mu.m. The resolving power is not affected.
However, when the substrate onto which the photopolymerizing layer is transferred becomes somewhat uneven and if the separating layer has the foregoing thickness, bubbles are enclosed between the photopolymerizing layer and the substrate, causing inferior transfer.
JP-A-2-213849 (the term "JP-A" as used herein means an "unexamined published Japanese patent application") discloses a transfer material having an interlayer of a polyvinyl alcohol derivative between a temporary support and a photosensitive resin layer. The interlayer is formed for improving the releasability of the photosensitive layer from the temporary support and the dissolution characteristics. However, no consideration is given to the transferring property of the photosensitive resin layer in the case where the substrate has an uneven surface.
Also, JP-A-63-309946 describes that since the sufficient adhesion of a transferred layer to a permanent support is obstructed by the existence of fine irregularity on the permanent support or the existence of fine particles such as fine dusts on the permanent support or the transferred layer, inferior transfer occurs. To prevent the undesirable inferior adhesion, a compressible temporary support is used. This technique is certainly effective, but is still insufficient for transferring a non tacky photosensitive resin layer, which becomes tacky at a temperature of not higher than 150.degree. C. but not-tacky at a room temperature, onto a permanent support having an unevenness of the same thickness as that of the photosensitive resin layer, as bubbles form between the photosensitive resin layer and the permanent support.

Photosensitive transfer material and image-forming process


A flush valve extension assembly retrofittable to a conventional water closet is disclosed which comprises a tube having a shoulder member extending outward from the outer surface of the tube in a position to form an upper section of the first tube having a predetermined length and to form a lower section of the tube which can extend into the flush valve seat, the shoulder member being sized to seat on the valve seat; a gasket fittable about the outer surface of the lower section in a position to form a water tight seal between the shoulder member and the flush valve seat; and a means fixable to the tube and extending about the overflow tube in a manner to attach the tube to the flush valve.

1. Field of the Invention
This invention relates in general to water closets, and more particularly, to flush valve extension assemblies retrofitable to existing flush valves used in water closets.
2. Prior Art
There has been a growing concern over the amount of water used by conventional water closets. This concern has been prompted in some geographical areas by the shortage of available water. In other areas the cost of treating municipal waste water before it can be recycled to a stream, lake or other water reservoir has prompted an examination into ways to minimize the amount of waste water that must be treated.
As a result of this concern many new water closet designs are now available which utilize substantially less water as the older designs. One example of the new designs is the Eljer "Ultra-One/G" which utilizes a tank trim to meter the amount of water that passes from the tank to the bowl during flushing. Other designs utilize tanks of less capacity and redesign the tank, flush valve and bowl system to create sufficient hydraulics to allow the water closet to properly discharge the waste and water in the bowl during flushing.
However, none of these solutions can be incorporated into the millions of existing water closets. Therefore, there is a serious need in the bathroom plumbing industry for an inexpensive device that can be quickly and easily fitted to existing water closets that will allow the use of less water when discharging the waste and water in the water closet bowl during flushing.


A main body of an illuminating knob is formed as a base made of a transparent resin. An undercoat layer and a topcoat layer are applied on a peripheral surface of the base. A pattern inside eliminating portion is formed in a shape of an indicating pattern as a marked portion by a laser etching or a partial exfoliation of the topcoat layer on the bottom portion. By passing light from a light source provided inside of the knob through the marked portion, an indication via passing through light is achieved.

1. Field of the Invention
The present invention relates to an illuminating knob used to operate various kinds of switch devices such as electric equipment for a vehicle.
2. Description of the Background Art
An example of an illuminating knob is explained based on the following illustrated example. FIG. 7 is a schematically explanatory view of a partial section of the illuminating knob, wherein the knob is substantially shaped in a bottomed cylinder. A window hole 3 is provided on a bottom portion 2 of a base 1 which functions as a main body made of a resin in which no light penetrates (hereinafter, refereed to as "non-penetration") due to the mixing of colored cosmetics or other material in the resin. An accommodating concave 4 with a hollowed inner side is formed on the bottom portion 2 including the window holes 3.
A lens 5, a transparent colored plate 6 and a louver body 7 are fitted in the accommodating concave 4 and light from a bulb 8 inside of the base 1 passes through the louver body 7. A slit 9 appears inevitably on a peripheral of the louver body 7 owing to a tolerance in the fitting portion.
FIG. 8 is a view showing an example of the louver body 7, wherein a transparent plate 11 is superposed on a louver 10 made of a non-penetration rubber. A marked layer 12, printed with non-penetration black paint, is formed on the transparent plate 11 and an inside of an indicating pattern is eliminated from the marked layer 12. A non-diffusion paint layer 13 is formed on a rear surface of the transparent plate 11.
Another transparent plate 14 is superposed on an opposite surface of the louver 10. The light from the bulb 8 passes through the louver 10 in a state of little dispersion and an indication is accomplished via the light passing through an eliminated portion of the marked layer 12.
At this time, because the dispersion of the penetrating light is lessened owing to the light passing through the louver body 7, such a problem wherein the light penetrates the marked layer 12 and disperses excessively and is reflected on a windshield of a car, is reduced.
The non-diffusion paint layer 13 makes an illuminating light to penetrate in a non-dispersion state when the illumination is not on such as during the daytime, the indication marked on the marked layer 12 is shown clearly by incident light from outside being reflected on the non-diffusion paint layer 13 after passing through the paint eliminating portion of the marked layer 12.
Generally, miniaturization is required for the operating knob of a switch. Especially, in the field of electric equipment for a car, miniaturization in both the dimension and weight of the car itself are required.
In the illuminating knob, the accommodating concave 4 should be formed on the bottom portion 2 where the louver body 7 is mounted to fit as in the above mentioned prior art. An area required for a mounting portion becomes necessarily larger. If the mounting portion is made small as it is, an indication pattern of the indication portion by the penetrating light is made small in proportion to the mounting portion. Thus, it is hard to see the pattern. Therefore, miniaturization of the base 1 has certain limits.
Further, in the mounting of the louver body 7, if the surface of the louver body becomes uneven with a circumferential surface of the mounting concave 4 of the bottom portion 2, the unevenness is apt to spoil an appearance and a touch feeling. Where dust is collected in the slit 9 formed on the circumference of the louver body 7, the appearance is also damaged.

Illuminating knob for switch and manufacturing method thereof


A system for measuring tire pressure and temperature including a pressure sensor, a temperature sensor, a processor responsive to an output of the pressure sensor and the temperature sensor, and a display. The processor is configured to output a value on the display indicative of a measured tire pressure and an indication of measured tire temperature, wherein the indication of measured tire temperature comprises an indication of the result of a comparison between the measured tire temperature and a predetermined temperature value.

Periodically checking a vehicle's tire pressures and tread depths is recommended to ensure its safe and efficient operation. As such, tire pressure gauges are popular tools for a driver to have at his or her disposal, as are tread depth gauges. It is also well understood that tire pressure is dependent on temperature. For example, when a vehicle with its tires initially at ambient temperatures (e.g. a vehicle that has been stationary for a period of time) is driven, the temperature of its tires generally increases, as the air within the tires is heated by, for example, friction generated between the tires and the road surface. This heating causes a corresponding increase in the tires' internal pressure. Likewise, changes in ambient temperatures affect a tire's internal pressure. As a result of this behavior, vehicle manufacturers generally supply recommended tire pressures which are associated with a particular temperature. More specifically, recommended tire pressures are typically given as "cold pressures", corresponding to the internal pressure of the tire measured when its temperature is around 20° C./68° F. to 22° C./72° F. (i.e. room temperature, hereinafter referred to as "nominal" temperature), as distinct from a "hot pressure", or a pressure measured when the tire's temperature is above this range. An exemplary "rule of thumb" used by many dictates that a change of temperature of +/−10° F. accompanies a rise or fall of pressure of about 1 psi. It follows that in order to accurately set tire pressures, knowledge of tire temperature at the time of measuring and/or filling/deflating may be required.
Alternative systems and methods for providing fast, convenient and accurate tire monitoring are desired.

Combination tire temperature, pressure and depth measuring device


An electrostatic discharge (ESD) protection device for a pushbutton module. A printed circuit board (PCB), a keypad unit, and a keypad marking board as well as an insulating sleeve and an electrical conductivity board isolate and discharge generated static electricity.

1. Field of the Invention
The present invention relates to an electrostatic discharge (ESD) protection device, and more specifically, to an ESD protection device for a pushbutton module.
2. Description of the Related Art
Electrostatic discharge (ESD) occurs in device measurement, packaging, installation, and usage, often damaging integrated circuits (IC) and affecting functionality. Three common models illustrating the formation of ESD are human body model, machine model, and charge device model. The human body model describes the ESD effect induced when the pin of an IC is contacted by a human being carrying electrostatic energy, defined according to Method 3015.6 of Military Standard (MIL-STD.-883). The machine model describes ESD induced when the pin of an IC is contacted by a machine carrying electrostatic energy, defined according to the measurement method in Method 20 of the Electronic Industry Association of Japan (EIAJ-IC-121) standard. The charge device model describes an ESD pulse generated in a charge carrying IC when contacting a grounded conductive element.
Most electronic devices experience ESD during 99% of their life cycle, and ESD interference in an electronic device can cause device lock up, restart, data loss, and reduced in reliability. ESD can seriously damage I/O ports, resulting in hardware breakdown and component damage.
Component failure is an obvious symptom of ESD damage, wherein contact with sensitive components destroys the components or microcircuits thereof. Although the electronic components subject to electrostatic discharge often suffer insignificant damage, the degradation of the middle layer is a potential issue as the expected lifetime of the component is less than claimed. ESD damage can accumulate, such that the performance of the influenced component varies from use to use. Another key effect of ESD is the influence on operation. The ESD generated energy can be mistakenly collected by the operating device as valid data, resulting in temporary failure during data transmission, or more seriously, physical damage to the device, such as damage to electronic components in a pushbutton module.
Push button switches are currently widely used, but the discussed ESD problems are is still an issue. In order to prevent electrostatic accumulation, an appropriate approach is required for avoidance of ESD generation.

ESD protection device, and pushbutton module and electronic device utilizing the same


A process for preparing aqueous pigmented ink jet inks with improved properties, comprising the steps of (a) charging a rubber two-roll milling apparatus with a pigment and a polymeric dispersant; (b) milling to obtain a dispersion of pigment with polymeric dispersant; and (c) dispersing the dispersion in an aqueous carrier medium.

Ink jet printing is a non-impact method that produces droplets of ink which are deposited on a substrate such as paper or transparent film in response to a digital signal. Ink jet printers, especially thermal or bubble jet drop-on-demand printers, have found broad application as output for personal computers in the office and the home.
Thermal ink jet printers use a plurality of nozzles, each containing a resistor element, to fire ink droplets toward the print media. Nozzle openings are typically about 40-60 micrometers in diameter. For proper operation of the printer, it is imperative that the ink jet ink not clog or plug these small openings. For pigmented ink jet inks in particular, it is necessary that the pigment particles be of small enough particle size so as to not clog the ejection orifice in the nozzle. Small pigment particles are also advantageous because they are less prone to settling during storage.
Pigment particles start in an agglomerated or flocculated state. Thus, it is necessary to disperse and stabilize the pigment so as to prevent flocculation and settling. The quality of the pigment dispersivity may also affect some ink jet printing characteristics such as ejectability, print quality, optical density, etc.
Ink jet inks have been made using a variety of different dispersion processes. U.S. Pat. No. 5,026,427 teaches the use of a liquid jet interaction chamber in the preparation of pigmented ink jet inks. U.S. Pat. No. 5,085,698 teaches the preparation of aqueous pigmented inks for ink jet printers using a media mill, a ball mill, an attritor, or a liquid interaction chamber. U.S. Pat. No. 4,597,794 teaches the preparation of pigmented ink jet inks by ball mill, roll-mill, speed line mill, homomixer, sand grinder, and the like.
T. C. Patton, "Paint Flow and Pigment Dispersion", John Wiley & Sons, N.Y., N.Y., p.386 (1979) discloses that a variety of different processes can be used to disperse pigments. These include ball and pebble mills, high speed disk impellers, high speed impingement mills, three-roll mills, high speed stone and colloid mills, sand mills, and batch attritors.
The term "roll mill" as used in the ink industry, refers to a three-roll milling apparatus. See, for example, Patton at p. 388:
The three-roll mill . . . is representative of the roller mills used by the coating and ink industries to grind (disperse) pigments into vehicles. Four-roll and five-roll mills are also manufactured, but except in ink preparation this extension of the three-roll principle has not taken hold in the paint industry. PA1 The roller mills--also called roll mills--which have been most commonly used in paint grinding are triple roll mills and single roll mills, although mills with up to five rollers are available.
See also Nylan and Sunderland, "Modern Surface Coatings", John Wiley & Sons, N.Y., N.Y., p 529 (1979):
Two-roll mills, on the other hand, have been widely used in the rubber industry (hence the name "two-roll rubber mills") to masticate rubbers, to blend in various components (e.g. antioxidants) or to mix different types of rubbers together. Such mills typically comprise a pair of horizontally disposed, spaced-apart, parallel, stainless steel cylindrical rolls which rotate inwardly toward one another. The distance between the rolls, known as the "gap," is variable, as is the temperature and rotational speed of each roll independently.
After much research and experimentation, the present Applicants have discovered that pigmented ink jet inks prepared from dispersions made using a two-roll mill have improved properties as compared to other dispersion techniques heretofore used to prepare ink jet inks, including three-roll mills or "roll mills."

Process for preparing ink jet inks having improved properties


A disinfecting and tidying device for a quilt includes a heating housing and a disinfecting unit. The heating housing includes a top cover and a bottom cover. The top cover and the bottom cover respectively include a frame and heating members configured in the frame. Portions of the frames of the top cover and the bottom cover adjacent to the open are curved. The disinfecting unit is located in the heating housing. The disinfecting unit and the heating housing together define a disinfecting room for accommodating the quit. The disinfecting unit is a hollow structure and includes an upper plate, a lower plate and a plurality of disinfecting members. Ends of the upper plate and the lower plate adjacent to the open are connected with each other in a curved manner. The disinfecting and tidying device can be used to disinfect, dry and tidy the quilt easily and conveniently.

1. Technical Field
The present invention relates to a device used for bedclothes in daily life, and more particularly to a disinfecting and tidying device for a quilt.
2. Description of the Related Art
Usually, human life has a third of the time spent in sleep. Sleep quality and sleep environment are very important for people. Naturally, beds, bedclothes and others supplied for sleep may influence sleep quality and sleep environment. Metabolism and perspiration will occur in sleep of human. The perspiration may wet the bedclothes. Specially, in some air moist areas, the bedclothes are easier to be moist. Warm and moist bedclothes are easy to breed bacteria. Therefore, if the bedclothes are neglected to clean and disinfect for a long time, the people's health would be affected.
In addition, health of the bedclothes in public health environment is also an important problem, such as hotels, hospitals and other public services. In order to prevent cross-infection and spread of bacteria, the bedclothes should be disinfected timely.

Disinfecting and tidying device for quilt


An astigmatic lenticular projector system includes a beam former for generating a family of planar light beams representative of an object; and an image former for diverging the light in each of the planar light beams transversely to the plane of the beams and not diverging the light along the plane of the beams for generating a viewable astigmatic image.

There are a number of well-known methods of projecting an image onto a screen where it can be viewed. Probably the earliest is the pin hole camera. This employs an opaque panel with a small hole through which light passes. Light reflected from a subject passes through the pin hole and strikes the screen where an image is formed. An advantage of this design is that the projected image is in focus at all distances between the screen, the pin hole, and the subject being projected; a disadvantage is its extreme optical efficiency. Of all the light that is reflected from the subject only a very small portion passes through the pin hole. This results in a very dim projected image.
A similar method of projecting an image replaces the pin hole with a lens. In this scheme light reflected from the subject passes through a lens and strikes the screen where the image is formed. The advantages are greatly improved optical efficiency. The lens collects far more of the reflected light than the pin hole of the previous scheme. The major disadvantage is that the positioning of the subject, the lens, and the projection screen must be set according to the well-known lens formula. If the positions are not correct then the image formed on the screen will be out of focus.
Another method of projecting an image involves sequential scanning. The image is generated by scanning a beam across the screen. If the scanning process is fast enough the eye will see a steady image. Early televisions produced an image by mechanically scanning a light beam across the screen in raster fashion. The intensity of the light beam was modulated to produce the image. The current television system uses a cathode ray tube (CRT) that has an electron beam that sequentially scans a screen of phosphorescent material. The phosphorescent screen emits light when struck by the electron beam. The image is produced by modulating the intensity of the electron beam.
The major advantage of the sequential scanning systems is that the image can be transmitted long distances electronically. A major disadvantage is that the image resolution is limited by the speed at which each pixel that makes up the image can be refreshed. The image must be refreshed at least 25 to 30 frames per second for television and 60 to 80 frames per second for computer or the human eye will see flicker in the generated image.
An image that has 1024 pixels by 1296 pixels and is refreshed at a rate of 80 Hz has a pixel clock rate of at least 106 MHz. This is a common set of parameters used in computers today. As the number of pixels increases the pixel clock rate must increase as well. This places a limit on the resolution that is obtainable with the current technology. Further, as the pixel speed increases the amount of energy delivered to each pixel on the screen decreases thereby making the image dimmer.
It is possible to create larger images by using multiple CRTs to create an image that is tiled together. The image on a CRT is not geometrically precise due to the difficulty in accurately positioning the electron beam. The tiled images do not line up well. This leaves gaps and distortion at the boundaries.


Provided are an optical coupler and an arrayed-waveguide grating structure including the same. The coupler includes a lower clad layer, a core comprising a slab waveguide region disposed on one side of the lower clad layer and a ridge waveguide region disposed on the other side of the lower clad layer, and an upper clad disposed on the core, wherein the ridge waveguide region comprises a self-focusing region configured to focus an optical signal provided form the slab waveguide region and thus to prevent scattering of the optical signal.

The present invention disclosed herein relates to an optical coupler and an arrayed-waveguide grating structure including the same, and more particularly, to an optical coupler having a self-focusing region and an arrayed-waveguide grating structure including the same.
An optical element for muxing/dumuxing of a signal in optical communication fields and photonic integrated circuit (PIC) fields may include a arrayed-waveguide grating (AWG), an Echelle grating, a ring filter or a Mach-2ehnder interferometer. Among them, the AWG is a wavelength division multiplexer (WDM) device which is the most widely used. As the AWG, a silica-based AWG and a silicon or InP-based AWG has been studied. Here, the silicon and the InP have a larger refractive index than that of the silica.
If a material having a large refractive index is used, a curvature radius thereof becomes smaller, and an optical loss is minimized, and thus a size of the AWG device may be reduced. A general insertion loss of the AWG may be about 3 dB, and thus, how to reduce the insertion loss of the AWG is very important task. The insertion loss of the AWG is caused by a slab waveguide, couple structures between the arrayed-waveguides, and a waveguide loss.

Optical coupler having self-focusing region and arryed-waveguide grating structure including the same

Electronics and Telecommunications Research Institute


The present invention provides an α-keto acid reductase isolated from Leuconostoc mesenteroides subsp. dextranicum, and a DNA encoding the reductase. The enzyme and homologs thereof reduce α-keto acids under the presence of NADH to produce optically active α-hydroxy acids. The α-hydroxy acids of the present invention include optically active mandelic acid derivatives of formula II. The optically active mandelic acid derivatives obtained by the present invention are useful as intermediates in synthesizing pharmaceuticals and pesticides

In general, enzymes not only have high catalytic activity but also exhibit stereospecificity, substrate specificity and reaction specificity. The stereospecificity of an enzyme is almost absolute with some exceptions.
According to recent research, the importance of the use of optically active substances in the field of pharmaceuticals, pesticides, animal foods, spices, etc. is increasing. Specifically, optical isomers sometimes have completely different physiological activities to each other, and thus techniques to specifically obtain optical isomers are important. For example, when only one of two enantiomers has the physiological activity of interest, the problem of a mixture of the enantiomers is not only that the other isomer has no activity in the mixture but also may competitively inhibit the coexisting effective enantiomer. Because of such competition, the biological activity of a racemate may be greatly decreased up to ½ as compared with that of the effective enantiomer. Therefore, it is an industrially important objective to develop methods for obtaining optically pure enantiomers (synthesis or resolution).
A technique widely used to achieve the objective comprises the synthesis of racemate followed by effective optical resolution of the synthesized racemate. However, according to this technique comprising the optical resolution after synthesis, an unintended enantiomer is always synthesized as a by-product. Thus, this technique is still problematic with respect to efficient utilization of raw materials. Even when the recovered by-product is regenerated as the raw material, a constant amount of by-product is always repeatedly synthesized. Hence, an enzymatic optical resolution method that neither produces a by-product nor produces a large volume of waste liquid has been attracting attention. The enzymatic optical resolution method utilizes specific generation of an objective enantiomer by taking advantage of the specificity of enzymes. This method suppresses the synthesis of unnecessary enantiomer so that they are produced at low levels. As a result of this method, products with high optical purity can be readily obtained. In addition, this method is advantageous for its efficient use of raw materials.
Optically active α-hydroxy acids include optically active mandelic acid, which is useful as an intermediate for synthesizing pharmaceuticals and pesticides. Known methods for producing optically active mandelic acid having a substituent on the benzene ring include the following:                optical resolution method comprising fractional crystallization of racemates (Unexamined Published Japanese Patent Application No. (JP-A) 2001-72644);        chromatographic optical resolution (Journal of Chromatography, 282, 83–8, (1983));        method using nitrilase (JP-A Hei 4-99496; JP-A Hei 6-237789);        method for obtaining an optical isomer by oxidizing one of the isomer in a racemate (JP-A Hei 6-165695); and        method using hydroxylnitrile lyase (JP-A 2001-354616).
The method using nitrilase requires a mandelonitrile derivative as the raw material. Sodium cyanide is necessary for the synthesis of the mandelonitrile derivative.
On the other hand, the method using hydroxylnitrile lyase requires benzaldehyde and hydrocyanic acid as the raw material. Due to its toxicity, hydrocyanic acid must be handled carefully.
A method for producing optically active mandelic acid by microorganism-mediated asymmetric reduction of phenylglyoxylic acid having no substituent on the benzene ring, is known in the art (JP-A Sho 57-198096; JP-A Sho 57-198097; JP-A Sho 63-32492; JP-A Hei 6-7179, etc.).
Methods for obtaining optical active substances of mandelic acid derivatives that have substituents on the benzene ring through enzymatic reactions will be of great use. However, no enzymatic method practicable on an industrial scale is known in the art.

α-keto acid reductase, method for producing the same, and method for producing optically active α-hydroxy acids using the same


The present invention relates to transformed plants and plant cells comprising DNA molecules encoding Bacillus thuringiensis proteins with insecticidal activity. The invention relates more particularly to transformed plants and plant cells comprising DNA molecules encoding the protease resistant toxins BTS02618Aa or BTS02618Ab, as well as to methods of rendering plants or plant cells resistant to insects using these DNA molecules.

1. Field of the Invention
This invention relates to four novel strains of Bacillus thuringiensis (the "BTS02617A strain", the "BTS02618A strain", the "BTS02654B strain" and the "BTS02652E strain"), each of which produces crystallized proteins (the "BTS02617A crystal proteins", the "BTS02618A crystal proteins", the "BTS02654B crystal proteins" and the "BTS02652E crystal proteins", respectively) which are packaged in crystals (the "BTS02617A crystals", the "BTS02618A crystals", the "BTS02654B crystals" and the "BTS02652E crystals", respectively) during sporulation. The BTS02617A, BTS02618A, BTS02654B and BTS02652E strains were deposited under the provisions of the Budapest Treaty at the Belgian Coordinated Collections of Microorganisms-Collection Laboratorium voor Microbiologie Belgium ("BCCM-LMG"), R.U.G., K. Ledeganckstraat 35, B-9000 Gent.
This invention also relates to an insecticide composition that is active against Lepidoptera and that comprises the BTS02617A, BTS02618A, BTS02654B or BTS02652E strain, as such, or preferably the BTS02617A, BTS02618A, BTS02654B or BTS02652E crystals, crystal proteins or the active component(s) thereof as an active ingredient.
This invention further relates to a gene (the "bTS02618A gene"), which is present in the genome of the BTS02617A, BTS02618A, BTS02654B and BTS02652E strains and which encodes an insecticidal protein (the "BTS02618A protoxin") that is found in the BTS02617A, BTS02618A, BTS02654B and BTS02652E crystals. The BTS02618A protoxin is the protein that is produced by the BTS02617A, BTS02618A, BTS02654B and BTS02652E strains before being packaged into their respective BTS02617A, BTS02618A, BTS02654B and BTS02652E crystals.
This invention still further relates to a toxin (the "BTS02618A toxin") which can be obtained (e.g., by trypsin digestion) from the BTS02618A protoxin. The BTS02618A toxin is an insecticidally active protein which can be liberated from the BTS02617A crystals, the BTS02618A crystals, the BTS02654B crystals, and the BTS02652E crystals, which are produced by the BTS02617A strain, the BTS02618A strain, the BTS02654B strain and the BTS02652E strain, respectively. This toxin and its protoxin have a high activity against a wide range of lepidopteran insects, particularly against Noctuidae, especially against Spodoptera and Aqrotis spp., but also against other important lepidopteran insects such as Pyralidae, particularly the European corn borer, Ostrinia nubilalis, Gelechiidae such as Phthorimaea operculella and Yponomeutidae such as Plutella xylostella. Furthermore, the BTS02618A protein is the first Bt protein with significant activity towards Acrotis seqetum. This new characteristic of the BTS02618A protoxin and toxin ("(pro)toxin"), i.e., the combination of activity against different economically important Lepidopteran insect families such as Noctuidae, Yponomeutidae, Gelechiidae and Pyralidae, makes this (pro)toxin an ideally suited compound for combatting a wide range of insect pests by contacting these insects with the (pro)toxin, e.g., by spraying or by expressing the bTS02618A gene in plant-associated bacteria or in plants. The BTS02618A toxin is believed to represent the smallest portion of the BTS02618A protoxin which is insecticidally effective against Lepidoptera.
This invention also relates to transformed Bacillus thuringiensis strains, containing DNA sequences encoding a BTS02618A protein or variants thereof having substantially the same insecticidal activity.
This invention yet further relates to a chimeric gene that can be used to transform a plant cell and that contains the following operably linked DNA fragments:
1) a part of the bTS02618A gene (the "insecticidally effective bTS02618A gene part") encoding an insecticidally effective portion of the BTS02618A protoxin, preferably a truncated part of the bTS02618A gene (the "truncated bTS02618A gene") encoding just the BTS02618A toxin; PA1 2) a promoter suitable for transcription of the insecticidally effective bTS02618A gene part in a plant cell; and PA1 3) suitable 3' end transcript formation and polyadenylation signals for expressing the insecticidally effective bTS02618A gene part in a plant cell. PA1 1) a cell (the "transformed plant cell") of a plant, such as corn or cotton, the genome of which is transformed with the insecticidally effective bTS02618A gene part, preferably the bTS02618A chimeric gene; and PA1 2) a plant (the "transformed plant") which is regenerated from the transformed plant cell or is produced from the so-regenerated plant and their seeds, the genome of which contains the insecticidally effective bTS02618A gene part, preferably the bTS02618A chimeric gene, and which is resistant to Lepidoptera. PA1 1) a microbial organism, such as B. thuringiensis or Pseudomonas spp., the genome of which is transformed with all or part of the bTS02618A gene; and PA1 2) a microbial spore, containing a genome which is transformed with all or parts of the bTS02618A gene. PA1 1) a DNA sequence encoding an insecticidally effective portion of the BTS02618Aa protoxin, preferably a truncated part of the bTS02618Aa gene (the "truncated bTS02618Aa gene") encoding just the BTS02618Aa toxin; PA1 2) a promoter suitable for transcription of the insecticidally effective bTS02618Aa gene part in a plant cell; and PA1 3) suitable 3' end transcript formation and polyadenylation signals for expressing the insecticidally effective bTS02618Aa gene part in a plant cell. PA1 1) a cell (the "transformed plant cell") of a plant, such as corn or cotton, the genome of which is transformed with the insecticidally effective bTS02618Aa gene part, preferably the bTS02618Aa chimeric gene; and PA1 2) a plant (the "transformed plant") which is regenerated from the transformed plant cell or is produced from the so-regenerated plant and their seeds, the genome of which contains the insecticidally effective bTS02618Aa gene part, preferably the bTS02618Aa chimeric gene, and which is resistant to Lepidoptera. PA1 1) a microbial organism, such as B. thuringiensis or Pseudomonas spp., the genome of which is transformed with all or part of a DNA sequence encoding the BTS02618Aa protein; and PA1 2) a microbial spore, containing a genome which is transformed with all or part of the bTS02618Aa gene.
This chimeric gene is hereinafter generally referred to as the "bTS02618A chimeric gene".
This invention also relates to:
This invention still further relates to:
Another embodiment of the present invention relates to artificially made bTS02618A genes which encode BTS02618A proteins, and to proteins which are more protease resistant than native Bt proteins, more preferably the native BTS02618A protein. A particular example of a protein that is more protease resistant is the BTS02618Aa protein. Furthermore, the present invention also relates to a DNA sequence encoding the BTS02618Aa protein.
Yet another embodiment of the present invention relates to a chimeric gene that can be used to transform a plant cell and that contains:
This chimeric gene is hereinafter generally referred to as the "bTS02618Aa chimeric gene".
This invention further relates to:
This invention still further relates to:
Yet another embodiment of the present invention relates to insecticidal compositions that are active against Lepidoptera and that comprise a more protease resistant Bt protein, more particularly the BTS02618Aa protein or a variant thereof which has substantially the same insecticidal activity.

Bacillus thuringiensis strains and their insecticidal proteins


The present invention relates to a method for operating a rotation sensor for detecting a plurality of rates of rotation about orthogonal axes (x,y,z). The rotation sensor comprises a substrate, driving masses, X-Y sensor masses, and Z sensor masses. The driving masses are driven by drive elements to oscillate in the X-direction. The X-Y sensor masses are coupled to the driving masses, and driven to oscillate in the X-Y direction radially to a center. When a rate of rotation of the substrate occurs about the X-axis or the Y-axis, the X-Y sensor masses are jointly deflected about the Y-axis or X-axis. When a rate of rotation of the substrate occurs about the Z-axis, the X-Y sensor masses are rotated about the Z-axis, and the Z sensor masses are deflected substantially in the X-direction.

A. Technical Field
The present invention relates to a micro rate of rotation sensor for detecting a plurality of rates of rotation about orthogonal axes x, y, and z, having a substrate, having a plurality of masses disposed in an X-Y plane parallel to the substrate and displaceable relative to the substrate, having a plurality of anchors for attaching the masses to the substrate, having springs for connecting at least some of the masses to at least one adjacent mass or to at least one anchor, having drive elements for oscillating at least some of the masses in the X-direction in order to generate Coriolis forces when the substrate is deflected, and having sensor elements for detecting deflections of the masses due to the Coriolis forces generated, and a method for operating a micro rate of rotation sensor for detecting a plurality of rates of rotation about orthogonal axes x, y, and z, having a substrate and driving masses, X-Y sensor masses, and Z sensor masses.
B. Background of the Invention
A generic micro rate of rotation sensor using MEMS technology is known from U.S. Pat. No. 6,308,567 B1, wherein driving masses are driven to oscillate. When a rate of rotation about one of the three orthogonal X, Y, or Z-axes occurs, masses are deflected out of the drive plane or rotated about the Z-axis. Sensor elements are associated with the masses in order to be able to detect the deflections. The deflections occur on the basis of Coriolis forces acting on the masses in case of a corresponding rotary motion and displacing the masses in the corresponding direction. In the embodiment example shown in said publication, the masses are driven toward a center and are rotated about an X-axis, a Y-axis, or a Z-axis due to the Coriolis forces. Sensor elements associated with said masses detect the corresponding rotary motion by means of electrical signals that occur by changing the spacing of fixed electrodes and displaceable electrodes. The signal change provides information about the rate of rotation that acted on the sensor.
A disadvantage of said embodiment is that such a sensor is very sensitive to external force effects, which can cause false measurements. The sensor shown also requires a large area on the substrate. The sensor is also sensitive to temperature, because deformation of the individual elements due to temperature effects can slightly falsify the results.

Micro rate of rotation sensor and method for operating a micro rate of rotation sensor


A method of making an emulsion ink is provided. The method includes mixing an ink precursor and processing the ink precursor in a homogenizer to form an emulsion ink. The ink precursor includes a pigment, water, a film forming polymer, an oil and, preferably, a pH dependent thickener and a base.

The present invention relates to ink compositions for use in pens, particularly ball-point pen inks.
While there are long-recognized advantages to using aqueous inks in ball point pens, the viscosity of these inks must be carefully adjusted in order to avoid flow problems, such as leakage around the ball. To adjust the viscosity, these inks have been thickened with natural gums, e.g., xanthan gum. Inks containing gums, however, often exhibit undesirable performance characteristics, such as blobbing and inadequate ink flow as the ink supply in the pen is depleted. Attempts have been made to overcome blobbing by using a very small ball, but pens having a small ball size tend to have a "scratchy feel" during use.
Aqueous inks also tend to lack smoothness, good writing consistency, and are prone to drying out at the ball tip when the pen is left uncapped.


A system for the abatement of industrial process gases utilizes a rotary regenerative oxidizer comprised of one or more heat exchange beds, each bed comprised of a parallel, axial, and longitudinal array of heat regenerative channels that thermally and/or catalytically oxidize contaminated gases. Utilizing a rotary regenerative oxidizer, and if desired, a plurality of heat regenerative beds incorporated therein, facilitates the use of regenerative technology at lower gas flow rates, increases thermal efficiency, and significantly reduces the floor space normally required when implementing fixed-bed nonrotary regenerative oxidizers. The heat exchange channels may be catalytically treated to enhance oxidation of the pollutants at a lower temperature.

The present invention relates generally to the abatement of contaminant laden industrial process gases and more particularly, to an abatement system which utilizes a rotary regenerative oxidizer.
Industrial process gases typically contain particulates and major gaseous air pollutants such as volatile organic compounds (VOCs) and carbon monoxide (CO), which contaminate the environment when vented to the atmosphere. Thermal and catalytic oxidizers are generally used to eliminate these contaminants. Thermal oxidizers utilize a supplementary heat source to increase the temperature of the inlet process gas to a level above the ignition temperature of the combustible contaminants, generally ranging from 1400.degree. F. (.apprxeq.760.degree. C.) to 1800.degree. F. (.apprxeq.980.degree. C.), so as to oxidize combustible contaminants such as VOCs and CO. Catalytic oxidizers further utilize a catalytic material to effect oxidation at lower peak temperatures.
Regenerative thermal and catalytic oxidizers (RTOs and RCOs) recover heat remaining in the cleansed exhaust gas, and through heat exchange, increase the temperature of gases entering the oxidizer thereby minimizing the amount of supplemental energy required to bring the gas to its ignition temperature. RTOs and RCOs generally operate in cycles and comprise a plurality of regenerative beds and a corresponding number of catalytic beds if an RCO is utilized. Characteristically, flow control valves are used to direct the inlet process gases to one or more regenerators for preheating prior to thermal or catalytic oxidation. RCOs and RTOs are generally of a fixed-bed design wherein the unit remains stationary as the process gases pass through for purification. One related concern is the relatively large floor space occupied by such a fixed-bed arrangement.
Catalytic oxidation, in contrast to thermal oxidation, reduces energy costs by lowering the reaction temperatures. Catalytic reaction temperatures typically range from 200 to 400.degree. C. as compared to 700 to 980.degree. C. required in thermal incinerators. However, catalytic reaction temperatures are still substantially greater than most flue gas temperatures and therefore, heat exchangers are frequently used as part of a control system to further lower the energy costs.
Regenerative or recuperative heat exchangers are commonly used in both RTOs and RCOs. Regenerative heat exchanger systems have a relatively higher thermal efficiency, typically 70 to 95%, while recuperative systems achieve at best 70% thermal efficiency. Most regenerative systems incorporate flow reversal design combined with heat sink packing material to achieve an optimum thermal efficiency. However, regenerative heat exchangers are expensive to implement and therefore, are generally only used for industrial process flow rates of approximately 850 Nm.sup.3 /minute or 30,000 SCFM (standard cubic feet per minute), or more. Recuperative heat exchangers are less expensive to implement, and thus are incorporated with industrial process flow rates of approximately 3 Nm.sup.3 /minute--850 Nm.sup.3 /minute or about 100--30,000 SCFM.
In a fixed-bed regenerative unit, the polluted gases first flow through an input heat regenerative bed, and then are oxidized before exiting the unit through an output heat regenerative bed. Heat absorbed by the process gases is transferred to the output heat regenerative bed for preheating of process gases subsequently entering the bed. Valve design facilitates process gas flow reversal and preheating thereof by directing the polluted influx into regenerative heat beds that functioned as output regenerative beds in the prior treatment cycle. A related concern, however, is that the characteristic flow reversal causes pressure fluctuations that may adversely affect the upstream process conditions. Furthermore, fixed-bed systems experience pressure drops, and as such, increased energy costs in order to maintain a consistent linear gas velocity.
Recuperative systems generally use a heat transfer surface as a medium to transfer heat, for example, in plate or shell designs. In addition to limited thermal efficiency, recuperative systems have associated mechanical concerns including condensation and corrosion. Condensation and corrosion are caused by uneven heating which forms "cold spots" on the heat exchange surface. Furthermore, use of a recuperative heat exchanger results in excess energy consumption due to high pressure drops across the heat exchange surface.


This invention relates to an isolated nucleic acid fragment encoding a farnesyltransferase subunit. The invention also relates to the construction of a chimeric gene encoding all or a portion of the farnesyltransferase subunit, in sense or antisense orientation, wherein expression of the chimeric gene results in production of altered levels of the farnesyltransferase subunit in a transformed host cell.

Lipids and proteins associate covalently to form lipid-linked proteins and noncovalently to form lipoproteins. The lipid portions of lipid-linked proteins anchor their attached proteins to membranes and mediate protein-protein interactions. Proteins form covalent attachments to lipids in several ways, one of which is the covalent attachment of isoprenoid groups, mainly the C15 farnesyl and C20 geranylgeranyl residues.
In mammals, geranylgeranyltransferase is known to catalyze the transfer of a geranyl-geranyl moiety from geranylgeranyl pyrophsophate to both cysteines in Rab proteins (Farnsworth, C. C. et al. (1994) Proc Nall Acad Sci USA 91(25):11963-11967). Rab proteins are Ras-related small GTPases that are geranylgeranylated on cysteine residues located at or near their C termini. Farnesyltransferase catalyzes the addition of farnesyl groups to the C termini of protein such as Ras.
Mammalian protein geranylgeranyl transferases types 1 and 2 are heterodimers composed of an alpha and beta subunit. The alpha subunit shows homology to the alpha subunits of a closely related enzyme, farnesyltransferase. Farnesyltransferases have been described in pea, tomato, and Arabidopsis, but have not been described in monocots (Yang et al. (1993) Plant Physiology 101:667-674). Plant farnesyltransferases also consist of alpha and beta subunits. The beta subunit is responsible for peptide-binding and contains a catalytic zinc ion. The beta subunit belongs to the protein prenyltransferase beta subunit family. The geranylgeranyl transferase beta subunit also belongs to the protein prenyltransferase beta subunit family. The beta subunits of the type 1 and 2 geranylgeranyltransferases have not been previously described in plants. Work done in yeast has established that protein geranylgeranyltransferases are distinct from the closely related protein farnesyltransferases.
It has been shown that defects in farnesyltransferase activity enhances plant hormone abscisic acid (ABA) levels. In a normal plant ABA levels increase in response to water deficits. An increase ABA in leaf tissue triggers the closure of leaf stomata to decrease water loss via transpiration (Pei et al. (1998) Science 282:287-290). Plants with a decrease in farnesyltransferase activity could confer enhanced tolerance to drought stress in plants. Thus, there is a great deal of interest in identifying the genes that encode farnesyltransferase in plants. These genes may be used in plant cells to control cell growth and produce plants with improved water stress tolerance. Accordingly, the availability of nucleic acid sequences encoding all or a portion of farnesyltransferase proteins would facilitate studies to better understand cell growth in plants, provide genetic tools to control cell growth and improve tolerance to drought in mature plants.


A mounting part (second member) 12 has a positioning hole 26 to be fitted to an outer peripheral side of a boss 18 disposed on a vehicle interior part (first member) 10, to be positioned thereto. A facing surface 24 of the mounting part 12 is formed into a flat surface. By a slidable-contact of the flat facing surface 24 with a tip end of the boss 18 for a positional alignment, the positioning hole 26 can be fitted readily to the boss 18. A tubular portion 28 is disposed on a surface at a side opposite to the facing surface 24 to be fitted to the boss 18 substantially over its entire length thereof. Such fitting maintains the aligned state, so that a fastening work during fixing of the mounting part 12 by screwing a mounting screw 30 into a cylindrical hole 16 of the boss 18 is facilitated.

1. Field of the Invention
The present invention relates to a member mounting structure and particularly relates to an improvement of a mounting structure, which with positioning a second member by a boss disposed on a first member, fixes a second member to the first member integrally by a mounting screw.
2. Description of the Prior Art
A mounting structure is known which presses a second member against a first member and integrally fixes it thereto. That is, in a state where a predetermined second member is positioned relative to a first member having a tubular boss with a screw fastening hole at its center using the boss as a reference, a mounting screw is screwed into the screw fastening hole. Thus, the second member is pressed against the first member and is thereby fixed integrally thereto by a head of the mounting screw.
A parts mounting apparatus disclosed in Patent Document 1 (Japanese Published Utility Model Application No. H 02-44106) is an example of such a structure. As shown in FIG. 5, a clock 102 is mounted integrally as a second member to a center cluster 10 which is an interior part for a vehicle as a first member. FIG. 5A is a longitudinal sectional view of mounting portions, and FIG. 5B is a perspective view of a supporting portion 120 as viewed from side of a positioning tube portion 124.
In FIG. 5, on a rear surface (upper surface in FIG. 5A) of the center cluster 100, a boss 106 of cylindrical shape having a screw fastening hole 108 at its center is protruded integrally at a periphery of a window hole 104. Four reinforcing ribs 110 are disposed radially on an outer peripheral surface of the boss 106. Meanwhile, the clock 102 has a supporting portion 120 in correspondence to the boss 106, on which a penetrating hole 122 is formed in correspondence to the screw fastening hole 108. At a circumference of the penetrating hole 122, a cylindrical positioning tubular portion 124 to be fitted to an outer peripheral side, that is fitted radially outward of the boss 106 protruding toward the center cluster 100, is provided. The positioning tubular portion 124 has four slits 126 provided for avoiding interference with the reinforcing ribs 110.
The clock 102 is positioned relative to the center cluster 100 so that the positioning tubular portion 124 is fitted to the outer peripheral side i.e. outer peripheral surface of the boss 106. In this state, a tapping screw 128 is screwed into the screw fastening hole 108 through the penetrating hole 122. The tapping screw 128 is thereby screwed to the screw fastening hole 108 while tapping an internal thread thereon, so that a head of the tapping screw 128 presses the supporting portion 120 against a tip surface of the boss 106 and thereby fixes it thereto integrally. Here, because the cylindrical boss 106 and the positioning tubular portion 124 are mutually fitted over a predetermined length, the positioning of the clock 102 is maintained satisfactorily, so that a fastening work by the tapping screw 128 can be performed readily.
FIG. 6 is a sectional view showing another conventional example. On a first member 130 which is a vehicle interior part, etc., a cylindrical boss 134 having a threaded hole 132 as a screw fastening hole at its center and protruding integrally is provided. On an outer peripheral surface of the boss 134, a plurality of reinforcing ribs 136 are disposed radially except for a predetermined axial length at a tip portion of the boss 134.
Meanwhile, a second member 140 is provided with a positioning hole 142 fitted to the outer peripheral side of the boss 134 to be positioned. The second member 140 has a thickness which is greater than the protruding dimension of the boss 134 from the reinforcing ribs 136. With the boss 134 fitted in the positioning hole 142 and the second member 140 contacted with reinforcing ribs 136, a mounting screw 144 is screwed into the threaded hole 132 of the boss 134. In this way, a head of the mounting screw 144 presses the second member 140 against the reinforcing ribs 136 to fix it integrally to the first member 130.
However, in the mounting structure of FIG. 5, because the boss 106 and the positioning tube portion 124 which are to be fitted mutually are disposed in a confronting manner, they must be positionally aligned in a mutually separated state before fitted together. This aligning process is troublesome, which hinders a good mounting workability and makes an automation of the mounting work difficult.
Also, unless the slits 126 formed in the positioning tube portion 124 and the reinforcing ribs 110 are aligned in positions thereof, the boss 106 and the positioning tube portion 124 cannot be fitted together. This also worsens an aligning workability as well.
Meanwhile, in the mounting structure of FIG. 6, the second member 140 is provided with the positioning hole 142. By adjusting position of the second member 140 with slidable-contacting with the tip end of the boss 134, the positioning hole 142 can be fitted readily to the boss 134. However, because the fitting length is less than thickness of the second member 140, there is a fear that the second member 140 may be detached or disengaged readily. In order to prevent such detachment, the fastening work of the mounting screw 144 must be performed while pressing the second member 140, which results in poor mounting workability. In this case, to improve the mounting workability, a positioning boss and a positioning hole must be provided additionally. Also, when the mounting screw 144 is fastened while the second member 140 rides on the boss 143, defective mounting structure is produced to worsen a yield.


An electrostatic actuator comprises a movable element provided with electrodes, and a stator provided with inductive electrodes for generating electrostatic induction in the electrodes of the movable element. The electrodes of the movable element includes a driven electrode part provided at a position opposite to the driving electrodes of the stator, and an induced electrode part provided at a position opposite to the inductive electrodes of the stator. The movable element is displaced relatively to the stator by generating electrostatic force between the driving electrodes of the stator and the driven electrode part in the movable element in which the electrostatic induction is generated, by applying a voltage to the driving electrodes of the stator, while generating electrostatic induction in the electrodes of the movable element through the induced electrode part by applying a voltage to the inductive electrodes of the stator.

1. Field of the Invention
The present invention relates to an electrostatic actuator which is operated by the action of static electricity, and a method of displacement.
2. Description of the Related Art
A conventional actuator and motor are operated mostly by the action of electromagnetic force, and the weights of the permanent magnet and iron core are heavy. Further, the loss of the current flowing in a winding causes enormous heat generation.
On the other hand, an ultrasonic actuator and an ultrasonic motor operated by forces other than electromagnetic force are known. They are driven by the frictional force of a piezoelectric transducer, but their life is too short due to deterioration caused by friction. Besides, for accurate positioning, it is necessary to control the position by using a position sensor such as an encoder. Further, for reducing the size of an ultrasonic actuator, it is necessary to increase the resonance frequency of a piezoelectric element. However, the increased frequency makes it difficult to operate at a low speed.
To solve these problems, several types of electrostatic actuator using electrostatic force have been researched and proposed. Two typical types have been proposed as an actuator capable of generating a relatively large force.
One is the electrostatic actuator disclosed in U.S. Pat. No. 5,448,124 or U.S. Pat. No. 5,541,465. This has a plurality of belt-like electrodes disposed with predetermined intervals in both stator and movable element, and displaces and drives the movable element by the electrostatic force between the stator and movable element by connecting/applying an AC power supply to the electrodes of both stator and movable element.
The other is the contact type electrostatic actuator disclosed in U.S. Pat. No. 5,239,222. This has a stator and a movable element, and applies electric charges from the stator to the movable element comprising a film having a predetermined surface resistivity, and obtains a displacement driving force by generating electrostatic force between the stator and movable element by utilizing a polarization time delay of a dielectric in the movable element.

Actuator adopting the principle of electrostatic induction


A coaxial capacitor is inserted in a coaxial cable in a predetermined position. A housing is provided as a ground conductor path in order to establish conduction between two external conductors in portions of the coaxial cable which are separated by the inserted coaxial capacitor. Inside the housing, a resonator formed by a dielectric coaxial resonator or the like, the coaxial capacitor, and a connecting conductor are accommodated.

1. Field of the Invention
The present invention relates to a band eliminate filter suitable for use in, for example, a high-frequency high-power system, and a communication apparatus including the band eliminate filter.
2. Description of the Related Art
Band eliminate filters for use in a high power system include an example as disclosed in Japanese Unexamined Patent Application Publication No. 11-274817 in which a waveguide and a cavity resonator are used. As shown in the above Publication, a problem in a filter for use in a high power system is discharge (arc discharge) at high power (high voltage). Also, recently, it is common that band eliminate filters are used in base stations for mobile communication. This case not only obviously requires measures for high power (high voltage), but also requires a filter having a very low loss in the vicinity of an attenuation range because of proximity of operating bands in recent years.
Although it is considered that the invention in Japanese Unexamined Patent Application Publication No. 11-274817 has durability against power and a low loss since the waveguide and the cavity resonator are used, the invention has a problem in that filter size is very large.
In addition, as shown in Japanese Unexamined Patent Application Publication No. 04-188902, Japanese Unexamined Utility Model Application Publication No. 06-066103, and Japanese Unexamined Patent Application Publication No. 02-034001, in each of commonly invented band eliminate filters, a dielectric resonator is used as a resonator, microstrip lines formed by a dielectric substrate are used as transmission lines, and a plane chip capacitor or a distributed-constant capacitor formed on the substrate is used as a capacitor. Although this type of band eliminate filter can be reduced in size, it has a possibility that many small gaps between electrodes may discharge at high power (high voltage), and the microstrip lines generally have large loss, thus causing a deterioration in insertion loss. Also, the chip capacitor and the capacitor formed on the microstrip lines cause a deterioration in insertion loss of a passband in the vicinity of an attenuation range since the capacitors each have Q.
When the passband is very close to the attenuation range, a reflection characteristic (return loss) in the vicinity of the attenuation range must be improved. For example, in the case of generating a return loss peak in the vicinity of the lower side of the attenuation range, the capacitance of the capacitors must be reduced. Due to the required characteristic, when the capacitance of the capacitors is very small, the use of the dielectric plane capacitor and the chip capacitor greatly reduces the size, so that assembly is difficult. In the case of the small size, differences in dimension precision of electrodes, dimension precision of dielectric material, and dielectric constant appear as a change in capacitance. Thus, a difference easily occurs in characteristics, which requires adjustment. Similarly, a difference in assembly easily appears as a change in capacitance, thus causing a difference in characteristics. For example, when a capacitance of 0.5 pF is obtained by a dielectric chip capacitor having a dielectric constant of 21 and a thickness of 1 mm, the shape of the chip capacitor is square, having each side of 1.63 mm. In this case, only a minute change of 0.05 mm in one side causes a 5-percent change in capacitance. Similarly, a change of 0.05 mm in thickness also causes a 5-percent change in capacitance. The 5-percent change generates a change of approximately 15 MHz in the return loss peak and a change of approximately 12 MHz in the attenuation peak. Also, since the case of adjusting the capacitance of the capacitors requires very high processing precision, a lot of experience is required.
FIGS. 8A and 8B show examples of characteristics of a band eliminate filter in which one stage of a resonator is coupled to a transmission line. FIG. 8A shows transmission characteristics S21 and S11 in a case in which the capacitance of the capacitor of the band eliminate filter is 0.290 pF, and FIG. 8B shows the transmission characteristics S21 and S11 in a case in which the capacitance of the capacitor of the band eliminate filter is 0.387 pF. In both cases, identical component values are used, except for the capacitance.
As shown in FIGS. 8A and 8B, when the capacitance of the capacitor for coupling the resonator with the transmission line changes only approximately 33 percent, the central frequency of the elimination band greatly changes from 1994.75 MHz to 1936.81 MHz. Also, an increase in the capacitance of the capacitor lowers the peak of the attenuation range, but increases the distance between the return loss peak and the peak of the attenuation range.

Band eliminate filter and communication apparatus


Disclosed is a duobinary optical transmission apparatus using a semiconductor optical amplifier (SOA). The duobinary optical transmission apparatus includes a light source for generating a carrier wave; a duobinary precoder for encoding an input (non return to zero) electric signal; a semiconductor optical amplification unit to amplify the encoded signal from the duobinary precoder, wherein the amplification unit receives an optical amplification gain difference that varies with a bias current combined with the encoded signal; and an optical band pass filter for receiving a phase-modulated optical signal from the semiconductor optical amplification unit, filtering the received optical signal to a prescribed bandwidth, and thereby generates a duobinary optical signal.

1. Field of the Invention
The present invention relates to a duobinary optical transmission apparatus using a duobinary optical transmission technique, and more particularly to a duobinary optical transmission apparatus using a semiconductor optical amplifier (SOA).
2. Description of the Related Art
In general, a dense wavelength division multiplexing (DWDM) optical transmission system transmits an optical signal using a single optical fiber in such a way that it enhances transmission efficiency. The optical signal comprises of a plurality of channels having different wavelengths. Also, the DWDM optical transmission system is widely used for superhigh-speed Internet networks. Such systems have a rapidly increasing data transfer quantity because it transmits optical signals irrespective of the transfer rate. Recently, systems for transmitting more than 100 channels via a single optical fiber using DWDM optical transmission methods have been commercially produced. In addition, other systems that simultaneously transmit more than 200 channels (each channel having a transfer rate of 40 Gbps) to accomplish a transfer rate of more than 10 Tbps are under development.
Such systems accommodate rapidly increasing data traffic as well as transfer requests for high-speed data transmissions of more than 40 Gbps. However, conventional optical intensity modulation methods using an non-return to zero (NRZ) method has a number of limitations. For example, one limitation is in increasing the transfer quantity because an abrupt interference and distortion between channels occurs in a prescribed zone less than a channel interval of 50 GHz. Further, nonlinear characteristics and dispersion are caused by propagating DC frequency components of a conventional binary NRZ transmission signal and high-frequency components spreading in the modulation procedure. Thus, the transmission distance is limited at high-speed transfer rates over 10 Gbps.
Recently, an optical duobinary technique has been intensively researched for obviating the transmission distance limitation caused by chromatic dispersion. The optical duobinary technique reduces the width of the transmission spectrum more than a general binary transmission method. The transmission distance in a dispersion limitation system is inversely proportional to a square of the transmission spectrum bandwidth. For example, when the transmission spectrum bandwidth is reduced by half, the transmission distance increases by four times. Also, a carrier wave frequency is suppressed in a duobinary transmission spectrum. This suppression reduces the limitations in output optical power caused by Brillouin Scattering stimulated in an optical fiber.
FIG. 1 is a block diagram of a conventional duobinary optical transmission apparatus. FIGS. 2a-2c are illustrate eye-diagrams of output signals at A, B and C nodes shown in FIG. 1, respectively.
Referring to FIG. 1, a conventional duobinary optical transmission apparatus includes a pulse pattern generator (PPG) 10 for generating a two-level NRZ electric pulse signal, a precoder 20 for encoding the two-level NRZ electric signal, low pass filters (LPFs) 30 and 31 for converting the two-level NRZ electric signal received from the precoder 20 into a three-level electric signal, and reducing the bandwidth of the three-level electric signal, drive amplifiers 40 and 41 for amplifying the three-level NRZ electric signal, and generating an optical modulator driving signal, a laser source 50 for generating a carrier wave; and a Mach-Zehnder-interferometer-type optical intensity modulator (MZ MOD) 60.
The two-level electric pulse signals generated by the PPG 10 are encoded by the precoder 20. An output eye-diagram at a node A is shown in FIG. 2a.
The two-level binary signal generated from the precoder 20 is transmitted to the LPFs 30 and 31. The LPFs 30 and 31 each have a bandwidth corresponding to about ¼ of a clock frequency of the two-level binary signal. This excessive bandwidth restriction causes interference between codes, and the two-level binary signal is converted into a three-level duobinary signal resulting from this interference between codes. An output eye-diagram at a node B is shown in FIG. 2b.
The three-level duobinary signal is amplified at the drive amplifiers 40 and 31, and the amplified three-level duobinary signal is used as a driving signal of the Mach-Zehnder-interferometer-type optical intensity modulator (MZ MOD) 60. The carrier wave generated from the laser source 50 modulates its own phase and its own optical intensity according to the driving signal of the MZ MOD 60. A two-level optical duobinary signal is thus generated. An output eye-diagram at a node C is shown in FIG. 2C.
Referring to FIG. 1, a reference character Q indicates an inverted signal of a signal Q. The signals Q and Q are respectively transmitted to a positive electrode (+) and a negative electrode (−) of the MZ MOD 60 with a dual electrode structure through the LPFs 30 and 31 and the drive amplifiers 40 and 41.
In this way, the MZ MOD 60 is classified into a Z-cut type MZ MOD and an X-cut type MZ MOD according to its own electrode structure. Referring to FIG. 1, the Z-cut type MZ MOD has a dual electrode and connects both of its own arms to the drive amplifiers 40 and 41 and the LPFs 30 and 31. This connection enables a three-level electric signal to be applied to each of the electrodes of the Z-cut type MZ MOD. Although the X-cut type MZ MOD, which has a single electrode, is not shown in the drawings, it connects one of its own arms to a drive amplifier and a LPF in order to transmit a three-level signal to one electrode.
However, such conventional duobinary transmission apparatuses are greatly affected by a pseudo random bit sequence (PRBS) because they generate a three-level electric signal using a LPF. Deterioration in the transmission characteristics increases with longer lengths of a PRBS. Thus, the overall system suffers. In particular, the system margin is greatly reduced for a 231-1 PRBS than a 27-1 PRBS. Typically, the slope along a signal's level change from a 0-level to a 1-level is different from the slope along a signal's level change from the 1-level to the 0-level. However, a duobinary optical transmission apparatus using LPFs suffers from increased jitters of the output waves since portions having different slopes are mutually summed, such that a first signal transition from 0-level to 1-level and a second signal transition from 1-level to 0-level are performed. This jitter problem is generated in both in the conventional Z-cut type or X-cut type structure. The dependency of such signal patterns limits the optical transmission operation.
In order to obviate the aforementioned problem, a structure without an electric LPF has been proposed. FIG. 3 is another conventional duobinary optical transmission apparatus using both a phase modulator and an optical band pass filter (BPF). Referring to FIG. 3, the PPG 10, a precoder 20, a modulator drive amplifier 40, and a laser source 50 are similar to those of FIG. 1. Such a duobinary optical transmission apparatus generates signals similar to duobinary optical output signals of FIG. 1 using a phase modulator 70 and an optical BPF 80 instead of an electric LPF.
Although, the aforementioned duobinary optical transmission apparatus guarantees a predetermined transmission quality according to the length of a PRBS, it must use a very expensive phase modulator. Consequently, the production cost of a transmitter is increased.

Duobinary optical transmission apparatus using a semiconductor optical amplifier


An IP bridge phone for operatively coupling one or more analog phones to a digital communications network to support parallel communications is disclosed. The IP bridge phone includes a phone handset interface adapted to connect to a phone handset, an analog phone interface, and a network interface. A mixing module is adapted to receive a first voice signal from the handset interface, a second voice signal from the analog phone, and a third voice signal from the data communications network; generate a plurality of combined signals from the first voice signal, the second voice signal, and the third voice signal; and transmit each of the plurality of combined signals to one of the plurality of interfaces. The plurality of combined signals provide parallel communications between the phone handset, the analog phone, and the remote calling party.

There are numerous residential and commercial environments having phones wired in parallel. In this familiar mode of operation, each of the phones rings in response to an incoming call, each of the phones may be used to answer the incoming call, and each of the phones may concurrently participate in an ongoing call by simply going off-hook. As illustrated in FIG. 1, a telephone system includes a plurality of conventional analog phones 120, 121 with handsets 130, 131 that may be wired in parallel directly to the Public Switch Telephone Network (PSTN) 100 or indirectly via a Private Branch Exchange (PBX) 110 or comparable server system and communications links 152, 154, 155 with conductor pairs commonly known as tip and ring lines. In a hotel, for example, the PBX (a) facilitates sharing of particular number of PSTN trunks with a relatively larger number of guest lines or phones, (b) supports room-to-room calling without involving the public network, (c) tracks phone usage so that guests may be billed for their telephone usage, and (d) enables/disables phone operation upon guest check-in/check-out from a room.
Illustrated in FIG. 2 is a typical sequence diagram for two analog telephone phones operating in parallel, although the operation applies more generally to three or more analog phones coupled in parallel. When an incoming call request, e.g., RING signal 202, 204, originating from the PBX 110 or PSTN, for example, arrives at and is answered by a first phone, an off-hook signal 206-207 is sent back to the PBX 110. Telephone voice signals 210-212 and subsequently transmitted between the PBX or PSTN and between the phone and associated phone handset 130. If a second phone 121 sharing a common tip and ring lines with the first 120 is off-hooked 216 during the ongoing conversation, audio signals are also exchanged between the second analog phone and its associated handset 131. If the first telephone 120 on-hooks before the second analog phone 121, the first handset voice signal 222 and the voice signals 228, 230 continue to be exchanged with the second telephone handset even though the first phone initially answered the call. Eventually the second phone 121 on-hooks 232 and the call is terminated.
With the rapid onset of Internet Protocol (IP) telephony into the marketplace, commercial institutions including hotels are motivated to upgrade existing analog telephone systems with IP telephones to enhance functionality and services not available with analog phones systems. With IP telephony operating data lines, hotel guests may be provided Internet access, caller-ID display, text message delivery, setup of wake-up calls, room service, account status, automatic checkout, and the like. In a number of instances, however, it is desirable for the hotels to replace some but not all guest analog phones with IP phones. For example, a hotel may wish to replace the analog phone at a hotel room's desktop with an IP phone while retaining the legacy analog phone commonly situated at the side of one or more beds as well as those analog phones at or near a bathroom.
While private branch exchange (PBX) systems have been adapted to support both IP and analog phones, there is currently no way to operate an IP phone and analog phone in parallel. Therefore, there is a need for a system and method to efficiently and cost effectively operatively couple IP and analog phones for paralleled voice communications.

Methods and devices for achieving parallel operation between IP and analog phones