A semiconductor device and a fabrication method thereof which are capable of enhancing the electrostatic capacity of a capacitor and preventing a short channel effect which occurs due to the decrease of a channel width. The semiconductor device includes a semiconductor substrate having a protrusion, a first insulation film formed on a lateral surface of the protrusion and on the semiconductor substrate neighboring with the protrusion, a conductive type sidewall spacer formed on the first insulation film, a first dopant region formed on an upper surface of the protrusion, a second dopant region formed in the semiconductor substrate in an outer portion from the conductive type sidewall spacer, an insulation film pattern formed on a surface of the conductive type sidewall spacer, a first conductive layer pattern contacting with the second dopant region and formed on the insulation film pattern, an interlayer insulation layer formed on an upper surface of the first conductive layer pattern, and a second conductive layer pattern formed on the interlayer insulation layer.

1. Field of the Invention
The present invention relates to a semiconductor device and a fabrication method thereof, and in particular to an improved semiconductor device and a fabrication method thereof by which it is possible to fabricate a dome-shaped semiconductor device.
2. Description of the Conventional Art
As a semiconductor device for increasing the integrity and electrostatic capacitance thereof, a pillar type capacitor of a conventional semiconductor device as shown in FIG. 1 and a fin type capacitor as shown in FIG. 3 have been used.
The conventional semiconductor device having a pillar type capacitor and a fabrication method thereof will now be explained.
First, FIG. 1 illustrates a conventional semiconductor device having a conventional pillar type capacitor. As shown therein, on a semiconductor substrate 1, a word line 2 is formed. Dopant regions 19a and 19b are formed in the semiconductor substrate 1 at both sides of the word line 2. The word line 2 acts as a gate electrode, and the dopant regions 19a and 19b act as a source electrode and a drain electrode, respectively. A silicon oxide film 3 which acts as an insulation film, is formed on the upper surface of the semiconductor substrate 1, and a silicon nitride film 4 is formed on the upper surface of the silicon film 3. A contact hole 19 is formed to pass through the silicon oxide film 3 and the silicon insulation film 4, respectively, and communicates with the drain electrode 19b. A polysilicon film 11 is formed within the contact hole 18 and on the upper surface of the silicon nitride film 4. At this time, the polysilicon film 11 acts as a node electrode 14 of the capacitor. An insulation film 12 which acts as a dielectric, is formed on the 5 polysilicon film 11 and the silicon nitride film 14. A conductive polysilicon film 13 is formed on the surface of the insulation film 12. The polysilicon film 13 becomes a plate electrode 13 of the capacitor. An insulation film 17 having a flat surface is formed on the upper surface of the plate electrode 13. A contact hole is formed in a portion of the source electrode 19a. A bit line 14 of a polysilicon layer which is a conductive layer, is formed on the upper surface of the insulation film 17 and on an inner surface of the contact hole is formed and is connected with the source electrode 19a.
The fabrication method of a semiconductor device having a pillar type capacitor will now be explained with reference to FIGS. 2A through 2H.
First, as shown in FIG. 2A, a gate electrode 2 made of a polysilicon is formed on the upper surface of the p-type semiconductor substrate 1, and an n-type dopant ion is implanted into the semiconductor substrate at both sides of the gate electrode 2 by a self-align method for thus forming the source electrode 19a and the drain electrode 19b, and then a multiple layer film 20 is formed on the upper surface of the semiconductor substrate 1 by a CVD (Chemical Vapor Deposition) method in such a manner that the gate electrode 2, the source electrode 19a, and the drain electrode 19b are surrounded thereby. The multiple insulation film 20 is formed by sequentially depositing a silicon oxide film 3, a silicon nitride film 4, and a silicon oxide film 5 on the upper surface of the semiconductor substrate. The silicon nitride film 4 is used as an etching finishing film.
Next, as shown in FIG. 2B, a contact hole 18 is formed by selectively and anisotropically etching the multiple insulation film 20 formed on the drain electrode 19b. A polysilicon layer is deposited on an inner surface of the contact hole 18 and the upper surface of the multiple insulation film 20. The first conductive layer 6 is used as a node electrode of the capacitor. A n-type dopant may be added to the first conductive layer 6 for increasing a conductivity of the first conductive layer 6. In the method for adding the n-type dopant, the n-type dopant is mixed with a deposition gas for forming the first conductive layer 6, so that the n-type dopant is added to the first conductive layer 6 at the time of depositing the conductive layer 6. In another method for adding the same, the first conductive layer 6 formed of a non-doped polysilicon layer is formed by the CVD (Chemical Vapor Deposition) method, and then the n-type dopant ion may be implanted by an ion implantation method. The first conductive layer 6 may be formed of a polysilicon layer, or the first conductive layer 6 may be formed of a high temperature melting metal or a silicide film formed of a high temperature melting metal.
Next, as shown in FIG. 2C, on the upper surface of the first conductive layer 6, a multiple insulation film 30 formed of a first silicon oxide film (non-doped silicate glass: hereinafter called a first NSG) 7, a P.sub.2 O.sub.5 -doped silicon oxide film (phosphor silicate glass: hereinafter called a PSG) 8, and a second non-doped silicon oxide film (non-doped silicate glass: hereinafter called a second NSG) 9 is formed. Thereafter, the multiple insulation film 30 is annealed at a temperature of about 900.degree. C. for about 20 minutes. The etching speeds of the first NSG 7, the PSG 8 and the second NSG 9 of the multiple insulation film 30 are different at the time of wet-etching, compared to the state that the annealing is not performed. An etching mask (not shown) is formed on the second NSG 9, and the multiple insulation film 70 is anisotropically etched by using the etching mask for thus forming a pattern having a vertical lateral surface on the first conductive layer 6 on the contact hole 18. When etching the resultant structure by a reactive ion etching method by using the photoresist film as an etching mask, and a chloro fluoro carbon as an etching gas, since there is an etching speed difference between the second NSG 9, the PSG 8, and the first NSG 7, it is possible to obtain a desired pattern having a vertical lateral surface.
Next, as shown in FIG. 2D, the multiple insulation film 30 formed of the second NSG 9, the PSG 8 and the first NSG 7 is wet-etched for about 2 minutes by using a 20:1 solution of NH.sub.3 :HF. At this time, when wet-etching the resultant structure by using the 20:1 solution of NH.sub.3 :HF, since the PSG 8 having a high density dopant has a high etching speed compared to the first NSG 7 and the second NSG 9, it is possible to obtain a pattern having a recessed etching lateral surface of the PSG 8 as shown in FIG. 2D.
Next, the second conductive layer 10 formed of a polysilicon layer having an n-type dopant as shown in FIG. 2E is formed on the upper surface of the first conductive layer 6 in such a manner that the second conductive layer 10 fully covers the NSG 9, the PSG 8 and the first NSG 7. Preferably, the second conductive layer is formed of a polysilicon layer having a dopant in order to reduce the resistance. The semiconductor substrate 1 is inserted into a chemical vapor deposition reactor, and the second conductive layer 10 is deposited in a state that the temperature of the chemical vapor deposition reactor is increased to a temperature of above 450.degree. C. in order to prevent the resistance from being increased as the insulation film is formed due to a natural oxide film formed on a boundary surface between the first conductive layer 6 and the second conductive layer 10.
The second conductive layer 10, as shown in FIG. 2E, is etched back by an anisotropical etching process until the second NSG 9 is exposed, so that the second conductive layer 10 remains on only the lateral surfaces of the second NSG 9, the PSG 8, and the first NSG 7 as shown in FIG. 2F.
As shown in FIG. 2G, the second NSG 9, the PSG 8, and the first NSG 7 are etched by using a hydrogen fluoride solution, and then the node electrode 11 of the capacitor is formed. At this time, the silicon oxide film 5 is also etched. In addition, since the silicon nitride film 4 is not etched with respect to the hydrogen fluoride solution, the silicon nitride film 4 is used as an etching finishing film.
An insulation film 12 which is a dielectric, is formed on the upper surface of the silicon nitride film 4 and the surface of the node electrode 11, and a conductive layer 13 is formed on the upper surface of the insulation film 12, as illustrated in FIG. 2H. The thusly formed insulation film 12 becomes a dielectric film of a capacitor, and the conductive layer 13 becomes a plate electrode 13 of the capacitor. An insulation film 17 is formed on the upper surface of the plate electrode 13, and then the semiconductor substrate 1 is flattened. The insulation film 17, the insulation film 12, the silicon nitride film 4, and the silicon oxide film 3 which are formed on the source electrode 19a, are etched for thus forming a contact hole. Thereafter, the polysilicon is deposited on the contact hole and then is patterned for thus forming a bit line 14 connected with the source electrode 19a and finishing the fabrication of a semiconductor memory device having a pillar type capacitor.
FIG. 3 illustrates a conventional semiconductor device having a fin type capacitor. As shown therein, a word line (not shown) is formed on the semiconductor substrate 1, and a gate electrode 2 connected with the word line 2 is formed therein. Dopant regions 19a and 19b are formed within the semiconductor substrate 1 at both sides of the gate electrode 2. The dopant regions 19a and 19b act as a source and drain electrode, respectively. An insulation layer 15 is formed on the upper surface of the gate electrode 2, a contact hole is formed on the upper surface of the source electrode 19a and is connected with the bit line 14 and the source electrode 19a, respectively. Another contact hole is formed in a predetermined portion of the drain electrode 19b and is connected with the node electrode 11 and the drain electrode, respectively, of the capacitor. An insulation film 12 which is a dielectric, is formed on the surface of the node electrode 11, and a plate electrode 13 of the capacitor is formed in such a manner that the plate electrode 13 surrounds the dielectric 12.
The conventional fabrication method for a semiconductor device having a fin type capacitor as shown in FIG. 3 will now be explained with reference to FIGS. 4A through 4G.
First, as shown in FIG. 4A, a word line (not shown) is formed on the upper surface of the semiconductor substrate 1, and the gate electrode 2 is connected with the word line. A dopant ion is implanted into the semiconductor substrate 1 at both sides of the gate electrode 2 for thus forming a source electrode 19a and a drain electrode 19b, respectively.
Next, as shown in FIG. 4B, a Si.sub.3 N.sub.4 film 15 which acts as an insulation film, is formed on the semiconductor substrate 1 by a chemical vapor deposition method in such a manner that the Si.sub.3 N.sub.4 film 15 covers the gate electrode 2.
As shown in FIG. 4C, a first silicon oxide film 60, a polysilicon layer 61, and a second silicon oxide film 62 are sequentially formed on the Si.sub.3 N.sub.4 film 15 which acts as an insulation film, and the first silicon oxide film 60, the polysilicon layer 61, and the second silicon oxide film 62 which are formed on the upper surface of the drain electrode 19b are etched for thus forming a contact hole 18 and exposing the drain electrode 19b.
As shown in FIG. 4D, a second polysilicon film 63 is deposited in the contact hole 18 and on the upper surface of the second silicon oxide film 62, respectively, and an n-type dopant is doped thereon in order to reduce the resistance of the second polysilicon film 63.
As shown in FIG. 4E, the second polysilicon film 63 is patterned, and the second silicon oxide film 62 is etched and is fully removed. Thereafter, as shown in FIG. 4F, the first polysilicon film 61 is patterned, and the first silicon oxide film 60 formed below the first polysilicon film 61 is etched and removed for thus forming a node electrode 11 of the capacitor as shown in FIG. 4F.
As shown in FIG. 4G, an insulation film 12 which acts as a dielectric, is formed on the surface of the node electrode 11 of the capacitor, and a polysilicon layer 13 is formed on the surface of the insulation film 12 for thus forming a plate electrode 13 of the capacitor. Thereafter, the insulation film 15 formed on the source electrode 19a is etched, thus forming a contact hole. A polysilicon layer is formed on the upper surface of the insulation film 15 and is patterned, thus forming a bit line 14 and finishing the fabrication of a semiconductor device.
As integration of the semiconductor device is increased, and a space for forming a capacitor therein is reduced, there is a limit for increasing the electrostatic capacity of a conventional capacitor. In addition, in the conventional semiconductor device, as integration is increased, the length of a word line is shortened, and the short channel effect occurs thereby. Furthermore, a contact error may occur in the source and drain electrodes, and a contact resistance may be increased, thus extending an operational time of a cell.

Method of fabricating dome-shaped semiconductor device


A capacitive motion encoder, for sensing the position of a moving object relative to a stationary object, includes at least one stationary element, coupled to the stationary object and a moving element, coupled to the moving object and in proximity to the stationary element. A field transmitter generates an electrostatic field, which is modulated by a change in capacitance between the stationary and moving elements responsive to relative motion of the elements. A conductive shield, is electrically decoupled from both the moving and the stationary objects, and encloses the moving and stationary elements so as to shield the elements from external electrical interference. Processing circuitry is coupled to sense the modulated electrostatic field and to determine responsive thereto a measure of the position of the moving object.

Measurements of rotation angle and of linear displacement are widely used in various fields for the control of position, velocity and acceleration. Non-contact sensors used for these purposes are described generally in the first chapter of the Synchro/Resolver Conversion Handbook, Fourth Edition, published by DDC ILC Data Device Corp. (Bohemia, N.Y., 1994), which is incorporated herein by reference.
Commercially-available, non-contact, full-rotation transducers (commonly known as rotation angle encoders) are almost exclusively either optical shaft encoders or electromagnetic resolvers. Both of these types of transducers are well known in the art. They are sold both as integrated devices, which include their own shaft and bearings, and as modular devices, to be mounted on a host shaft.
Optical encoders provide binary level output signals and can be divided into absolute and incremental types. Encoders of the latter type are more popular, due to their flat construction and low cost, despite suffering from the following shortcomings:                Only relative position is measured.        Such encoders are sensitive to mechanical assembly and mounting errors.        The construction of such encoders affords only limited mechanical durability.
Absolute optical encoders are more expensive, more bulky and usually non-modular. In recent years, a modified absolute encoder was introduced, which provides sinusoidal, rather than binary-level, outputs, which can be interpolated to provide enhanced resolution.
Electromagnetic resolvers, which are described in detail in the above-mentioned Synchro/Resolver Conversion Handbook, are wound inductive components. They are relatively bulky and expensive, but highly durable. Single pole-pair resolvers provide two output voltages, which are proportional to sin θ and to cos θ, wherein θ is the rotation angle. Multi-pole-pair resolvers provide output voltages proportional to sin(nθ) and to cos(nθ), wherein n is the number of pole pairs. The resolution and accuracy of the multi-pole-pair resolver are high, but the output signals do not define the rotation angle unambiguously over a full rotation.
The two-speed resolver is equivalent to a combination of a single pole-pair and a multi-pole-pair resolver on the same shaft. It provides, simultaneously, two pairs of output voltages, which are referred to as coarse and fine channels. By processing both channels, an accurate and unambiguous reading is obtained. This kind of resolver, however, is even more bulky and expensive than its single or multi-pole-pair counterparts.
Linear optical encoders are incremental digital devices which, like incremental rotary encoders, include a reading head which moves relative to a ruler and generates output pulses. Currently, high-accuracy, long-stroke, linear encoders are almost exclusively of the optical type, although there are also some linear encoders based on magnetic principles. There is no capacitive linear encoder that is available commercially as a stand-alone component, but linear capacitive encoders are widely used in digital calipers.
In the context of the present patent application and in the claims, the term "encoder" refers to displacement transducers in which the interaction between the stationary and moving elements is based on a repetitive pattern, with a either binary or continuous output signal. The terms "moving element" and "rotor" are used interchangeably with reference to rotary encoders, as are the terms "stationary element" and "stator." Likewise, the terms "reading head" and "ruler" refer respectively to the moving and'stationary elements of linear encoders.
Even after many years of development, neither optical shaft encoders nor electromagnetic resolvers provide all of the following desirable features in combination:                Absolute reading with high accuracy and resolution.        Simple construction and low-profile packaging.        Low manufacturing costs.
Basic Concepts of Capacitive Rotation Angle Encoders
Capacitive, full-rotation, absolute angle encoders (CFRAAEs) convert rotation angle into an output signal based on capacitive interaction between a rotor and a stator. They can be built to emulate the single-pole or multi-pole electromagnetic resolver, i.e., with an output signal that repeats once or more times per rotation, as well as multi-speed resolvers.
CFRAAEs, as described in the patent literature, would be expected to provide significant advantages over optical and inductive encoders. But CFRAAE devices have been entirely absent from the market as the result of a variety of difficulties, not all of which have been fully identified, appreciated, or solved. For example:                Accurate CFRAAE operation demands the discrimination of capacitances under one Femto-Farad (10−15 Farads) in the presence of parasitic capacitances and extraneous interference. Shielding against external interference is therefore of paramount importance.        It has been assumed that CFRAAs requires costly, highly-accurate and stable electronic components. For example, German patent application DE 42 15 702 describes a capacitive angle encoder in which capacitances are individually corrected by laser trimming.        In CFRAAEs described in the patent literature, complex signal conditioning is required. Signal processing systems for use in this context are described, for example in German patent application DE 36 37 529 and in a corresponding U.S. Pat. No. 4,851,835, which is incorporated herein by reference.        There has been a lack of systematic classification and analysis of the various known encoder types. Consequently, novel configurations and possibilities for improvement have not been discovered.
It has therefore been the prevailing view in the field that a CFRAAE could not be commercially feasible. Only limited-rotation (substantially less than 360° ) capacitive transducers have found practical use, and only in limited applications in which the transducer is integrated in a host system, mainly in optical mirror scanners. Typical limited-rotation transducers are described in U.S. Pat. Nos. 3,312,892, 3,732,553, 3,668,672, 5,099,386 and 4,864,295, which are incorporated herein by reference.
Analog full-rotation transducers, such as electromagnetic resolvers (in contrast with digital, or pulse-counting) transducers, typically provide two orthogonal output signals proportional to the sine and cosine of the rotation angle. Since capacitive coupling, unlike inductive coupling, is always positive, the only way, in general, to obtain a bipolar output in a capacitive transducer is to measure the difference between two displacement-dependent capacitances.
FIG. 1 is a typical schematic circuit diagram illustrating this principle (which is also applicable to capacitive linear displacement transducers). Two complementary excitation voltages Q and Q′ are applied to stationary transmitter plates 41 and 42, respectively. A moving receiver plate 40 is capacitively coupled to both transmitter plates and is connected to a charge amplifier 43, as is known in the art. The output voltage of the charge amplifier 43 is proportional to the difference of the respective capacitances C1 and C2 between receiver plate 40 and transmitter plates 41 and 42. The output of amplifier 43 is processed to provide the amplitude and polarity of the differential capacitance C1–C2, from which the position of plate 40 relative to plates 41 and 42 can be derived.
By analogy with electromagnetic resolvers, CFRAAEs can be made in both single-pole and multi-pole configurations. U.S. Pat. No. 5,598,153, which is incorporated herein by reference, describes a typical single-pole CFRAEE. French patent application 77 29354 describes a multi-pole encoder, in which the overlap between the rotor and a stator varies six times per revolution. The above-mentioned U.S. Pat. No. 4,851,835 describes an encoder in which a single rotor generates both coarse and fine signals.
Various methods are described in the relevant patent literature for converting a variable capacitance into output signal. The methods can be divided into two families:                1. Incorporating the variable capacitance in an oscillator circuit, which responds by varying its frequency, or duty cycle. Such methods are described, for example, in European patent application 0 459 118 A1; in German patent application DE 33 28 421; and in an article entitled "Kapacitives Sensorprinzip zur Absoluten Drehwinkelmessung" (A capacitive sensor principle for absolute angle of rotation measurement), by Arnold and Heddergott, in Elektronpraxis (March, 1989).        2. Incorporating an AC excitation source for obtaining at least one AC or DC output signal which is a function of angle-dependent capacitances in the encoder. Two such outputs are required if a full rotation is to be covered. For example, U.S. Pat. No. 4,092,579, which is incorporated herein by reference, describes a capacitive resolver having one excitation voltage source and two output voltage signals proportional, respectively, to the sine and cosine of the rotation angle. U.S. Pat. No. 4,429,307, also incorporated herein by reference, describes a capacitive encoder with a similar circuit arrangement, except that two excitation voltages of opposite polarities are used.
Similar approaches are described, for example, in European patent application 0 226 716; in German patent application DE 36 37 529; and in an article entitled "An Accurate Low-Cost Capacitive Absolute Angular-Position Sensor with A Full-Circle Range," by Xiujun Li, et al., in IEEE Transactions on Instrumentation and Measurement, 45:2 (April, 1996), pp. 516–520.
The accuracy of such CFRAEE schemes based on AC excitation depends on the quality of the excitation voltages. Inaccuracies may result to the extent that the excitation signals are not of high harmonic purity and equal in amplitude, or if there is deviation from exact 90° relative phase shift. The difficulties entailed can be overcome by circuit complexity, as illustrated by FIG. 3 in the above-mentioned German patent application DE 36 37 529. Solutions include complex digital emulation of the analog sinusoidal voltages, as proposed in European patent application 0 226 716, or employing accurate and stable analog circuit elements, as in the above-mentioned article by Li, et al.
German patent application DE 37 11 062 also describes a capacitive position measuring device using AC square wave excitation. The rotation angle is computed based on time sampling of a stepwise signal that results from interaction of the square wave excitation voltages with capacitance that varies with the rotor rotation (as shown in FIG. 2-d of that application). The disadvantage of such discrete sampling is an inferior signal-to-noise ratio (SNR), since sampling of the input voltage ignores its values between sampling times and is prone to noise.

Linear electric encoder with facing transmitter and receiver


An aqueous ink jet composition comprising a pigment dispersion, an aqueous carrier medium, and a cosolvent mixture comprising a polyol/alkylene oxide condensate and a cyclic amide derivative have excellent print quality due to high optical density and minimum feathering over a wide range of commercial papers having different properties, dry rapidly by media penetration without excessive loss of image definition, and become 100% waterfast as soon as the inks are dry to the touch.

Ink jet printing is a non-impact printing process in which droplets of ink are deposited on a substrate such as paper or transparency film in response to an electronic signal. Low cost and high quality of the output, combined with relatively noise free operation, have made ink jet printers a popular option to other types of printers used with computers. In thermal ink jet printing, a resistor element in a chamber is provided with an egress for the ink to enter from a plenum. The plenum is connected to an ink reservoir. A plurality of such resistor elements are arranged in a particular pattern in a print head. Each resistor element is associated with a nozzle in a nozzle plate, through which ink is expelled onto the print medium. The entire assembly of print head and reservoir comprise a thermal ink jet pen.
In operation, each resistor element is connected to a microprocessor, whose signals cause one or more elements to heat up rapidly. The heat creates a vapor bubble in the chamber, which expels ink through the nozzle onto the print medium. Firing of a plurality of such resistor elements in a particular order forms alphanumeric characters, area fills, or other indicia on the print medium.
Both dyes and pigments have been used as ink colorants for ink jet printers. However, dye-based inks generally suffer from deficiencies in water fastness, and lightfastness. Pigments are a preferred alternative to dyes, provided the pigment dispersions can be made stable to flocculation and settling.
Water based pigment dispersions are well known in the art, and have been used commercially for applying films such as paints onto various substrates. They are generally stabilized by ionic or non-ionic dispersants. While the pigments are inherently more lightfast than the dyes, the choice of the dispersant has a direct effect on ink properties such as waterfastness and smear resistance.
Three attributes of ink jet inks of prime importance are 1) print quality they produce, 2) drying rate when placed on the substrate, and 3) reliability. Print quality is mostly determined by factors such as optical density of the print, edge acuity, dot shape, and spray, if any. To a lesser degree, print quality is also determined by the printer mechanics such as resolution, drop volume, drop velocity, and the software controlling the print modes. But, it is the ink/paper interaction that has the dominant influence on print quality. Paper quality varies depending on the manufacturing process. An ink therefore would interact differently with different commercial papers. Inks that produce high print quality independent of the print media are hence highly desirable.
Drying rate, among other factors, determines the printer throughput. Ink jet printer throughput is relatively slow compared to printers using competing technologies. This is mainly due to "slow" drying rate of the ink jet inks. Inks usually dry by two mechanisms: evaporation and penetration. Evaporation is determined by the vehicle vapor pressure, whereas penetration is determined by the interfacial energy between the ink and the paper and the porosity of the paper.
Heating devices may be used to enhance drying. However, this also accelerates solvent evaporation from the nozzles and causes nozzle plugging. Heaters also add to the printer cost. The use of penetrating cosolvents and surfactants as means of improving dry time is well known in the art. However, many known penetrants, such as butyl carbitol, tend to destabilize pigment dispersions; surfactants also destabilize and/or increase feathering, resulting in degraded print quality.
The ink related reliability issues include 1) decap or crusting time which is defined as the time period over which a print head can stay dormant and exposed to the atmosphere without failing to print; 2) drop volume consistency over pen life; 3) compatibility with the print head components; 4) long term storage stability; and 5) robustness towards variable print parameters such as the firing frequency and pulse width.
The three major ink attributes discussed above conflict with each other. For example, methods known to increase drying rates such as the use of volatile cosolvents adversely affect either print quality by causing increased feathering or reliability by adversely affecting the crusting performance. U.S. Pat. No. 4,986,850 teaches that improved print optical density and edge acuity results from the use of up to 4.5% by weight of an alkylene oxide adduct of a polyhydric alcohol in the ink, which increases the viscosity of the ink due to solvent evaporation when printed on the substrate. This approach, however, also results in longer drying times and an increase in ink viscosity in the nozzles during dormant periods, which causes print reliability problems.
Accordingly, a need exists for inks that will produce high optical density, high print quality and permanent prints over a wide range of papers. A need also exists for inks that dry fast, print reliably and are stable for long periods of storage. This invention satisfies these requirements by using a stable pigment dispersion and a cosolvent system which makes the ink penetrate effectively for achieving the required balance between dry time and spreading.


An integrated circuit for receiving data includes an input receiver circuit that is supplied with a data signal and a reference signal. The input receiver circuit converts the data signal into differential input control signals that are supplied to first and second signal paths. The first and second signal paths being connected in parallel. The first signal path includes a first comparator circuit that is connected, via a delay circuit and an amplifier circuit, to an output connection of the integrated circuit. The second signal path includes a second comparator circuit that is likewise connected, via a first inverter circuit and a second inverter circuit, to the output connection of the integrated circuit. The two amplifier circuits act as edge discriminators that drive each other and make it possible to generate, at the output connection, an output signal with the same duty cycle as the data signal without distortion.

An integrated semiconductor memory, for example a DRAM (Dynamic Random Access Memory) semiconductor memory, generally includes control connections for applying control signals, address connections for applying address signals, and data connections for applying data. In the event of a write access operation, a write command is applied to the control connections and an address signal is applied to the address connections. This makes it possible to activate at least one memory cell in a memory cell array of the integrated semiconductor memory for a write access operation.
The data to be stored is applied to the data connections which are connected to receiving circuits in the semiconductor memory. The characteristic variables of the specification for a receiving circuit for receiving data include the set-up times and hold times. The latter are used to specify the time for which a data item must be applied at least to one of the data connections in order to be able to read the data item into the semiconductor memory in a clear and reliable manner. As a result of the increase in the access speed and thus in the operating frequency during the development of semiconductor memories in recent years, the time window in which valid data is applied to the semiconductor memory has become increasingly small. The receiving circuits must therefore accept the data into the semiconductor memory from the data connections within a very small time window.
FIG. 1 shows an integrated circuit ES′ of a semiconductor memory, in which a differential amplifier D is connected to an input connection E1 for applying a reference signal VREF and to an input connection E2 for applying a data signal (e.g., an input signal) DQ. The differential amplifier D compares a level of the data signal DQ with a level of the reference signal VREF and generates, at the output, an output signal which has a high or low level, is amplified by downstream amplifiers V1 and V2 and is forwarded to an output connection A. From there, the amplified data signals are generally supplied, via read/write amplifiers, to a memory cell array of an integrated semiconductor memory.
As shown in FIG. 1, input signals for the integrated semiconductor memory, for example the data signals DQ, are received using a differential amplifier. The problem with this is, in particular, that the differential amplifier is not driven by differential input signals but rather by an input signal level and a constant reference signal level. In this case, different delays generally arise when receiving a rising or falling edge of the input signal. This consequently produces, at the output connection A, an output signal whose duty cycle is distorted with respect to the input signal. If, for example, the differential amplifier is supplied with an input signal which, during a clock period, has a high level for half of the period duration and a low level for the other half of the period duration, an output signal in which the high and low levels have different durations is produced at the output connection A.


A method to save time needed in battery replacement for a Notebook and a battery detector thereof is comprised of having placed the battery detector containing a voltage detection circuit and a register module in the Notebook. When the power level of the battery falls below a first threshold, a prompt menu including a battery replacement option is displayed. When battery replacement option is selected, the Notebook enters a sleep mode and a numeric value marking the need of an automatic power on for the Notebook is stored in the register module. If the voltage detected by the voltage detection circuit is greater than a second threshold, and a numeric value marking the need of an automatic power on for the Notebook is stored in the register module, the Notebook is driven to perform a power on procedure.

(a) Field of the Invention
The present invention is related to a battery power control circuit and its control method, and more particularly, to one that shortens the battery replacement time for a Notebook.
(b) Description of the Prior Art
Battery in a Notebook usually maintains its level for use of 2˜4 hours. Once the battery power is consumed up, the user has to either use a power line to obtain operating power from a power socket, or closes the running application and powers off the notebook for replacing the battery. However, it is not very convenient for a user who spends longer time with his Notebook since it takes a couple of minutes to replace the battery and activate the interrupted application all over again.

Notebook battery replacement time-saving method and battery detector thereof


Message retrieval methods and devices allow for the remote retrieval of caller identity delivery (xe2x80x9cCIDxe2x80x9d) information or messages stored in telephones, telephone answering devices (xe2x80x9cTADxe2x80x9d) and the like through the use of dual-tone, multi-frequency (xe2x80x9cDTMFxe2x80x9d) signals.

The number and usage of CID storage devices and other similar message storage devices has grown over the last few years. Typically, these devices store CID information which can only be xe2x80x9cretrievedxe2x80x9d by visually viewing the information or messages on a display screen or the like. The messages most commonly take the form of a telephone number.
The need to visually retrieve messages imposes certain limitations on the use of these devices. For example, if a user of such a device is remotely located from the device it is practically impossible to retrieve messages.
Accordingly, it is an object of the present invention to provide for methods and devices which allow for the remote retrieval of stored CID information or messages.
It is another object of the invention to provide for a programmed device, such as a microprocessor, digital signal processor or any combination of components which perform similar functions, which comprises a program memory and program code for sending or transmitting CID information or messages.
Other objectives, features and advantages of the present invention will become apparent to those skilled in the art from the following description taken in conjunction with the accompanying drawings.
In accordance with the present invention there are provided devices for sending CID information to a remote communications device. Such devices may comprise: receiving means or a receiving unit for receiving an input signal, where the input signal may comprise an access code, local input signal, or remote input signal; addressing means or an addressing unit for addressing a remote communications device identified by an address code, where the address code may comprise a telephone number or paging telephone number, the addressing may occur after verification that the received input signal matches a stored code, the stored code may comprise an access code and where the access code may in turn comprise a DTMF signal or signals; transmission means or a transmission unit for transmitting stored CID information to the addressed communications device, where the CID information may comprise CID messages or DTMF signals; first memory means or memory unit for storing the CID information; where the transmission means or unit may further comprise means for transmitting an OGM message to prompt input of the input signal and means or a unit for transmitting a signal, such as a star tone signal, in between transmission of stored CID information; verification means or a verification unit for verifying that the received input signal matches a stored code, where the stored code may comprise an access code; detection means or a detecting unit for detecting a call termination signal, where addressing may occur after detection of a call termination signal; receiving means or a receiving unit for receiving a message entry tone, where transmission of CID information may occur after receipt of a message entry tone; halting means or a halting unit for halting the transmission of CID information upon receipt of a second input signal, where the second input signal may comprise a pager full signal or paging system full signal; second memory means or memory unit for storing CID messages; detection means or a detection unit for detecting the presence of a full or partial CID message in a second memory unit; transmission means or a transmission unit further adapted to transmit a full CID message upon detection of a partial CID message in a message memory; halting means or a halting unit for halting transmission of the CID information upon transmission of all of the stored CID information; receiving means or a receiving unit for receiving an address code which identifies a remote communications device; selection means or a selecting unit for selecting an address code, associated with a received access code, from stored address codes. The device may further comprise a telephone, standalone CID device, a TAD, a PBX system or a combination of a CID and TAD device. The remote communications device may comprise a pager or paging system.
In accordance with other embodiments of the present invention programmed devices are provided which send or transmit stored CID information or messages to a remote communications device. Such devices may comprise program memory means or a program memory. The program memory may comprise: program code or program code means for addressing a remote communications device identified by an address code upon receipt of an input signal, where the input signal may comprise an access code, local input signal or remote input signal and where the address code may comprise a telephone number or paging telephone number; program code or program code means for transmitting stored CID information to an addressed communications device, where the CID information may comprise CID messages or DTMF signals; program code or program code means for transmitting an outgoing (xe2x80x9cOGMxe2x80x9d) message to prompt input of an input signal; program code or program code means for verifying that a received input signal matches a stored code, where the stored code may comprise an access code and the access code may comprise a DTMF signal; program code or program code means for addressing a remote communications device after verification that a received input signal matches a stored code, where the stored code may comprise an access code; program code or program code means for detecting a call termination signal, where addressing may occur after detection of the call termination signal; program code or program code means for transmitting CID information after receipt of a message entry tone; program code or program code means for transmitting a signal, such as a star tone signal, in between transmission of stored CID information; program code or program code means for halting the transmission of CID information upon receipt of a second input signal, where the second input signal may comprise a pager full signal or paging system full signal; program code or program code means for detecting the presence of a full or partial CID message in a message memory; program code or program code means for transmitting a full CID message upon detection of a partial CID message in a message memory; program code or program code means for halting transmission after transmitting of all stored CID information; and program code or program code means for selecting an address code, associated with a received access code, from stored address codes. The programmed device may further comprise, for example, a telephone, digital signal processor, microprocessor or the like. The remote communications device may comprise, for example, a pager or paging system.
Other embodiments of the present invention provide for methods for sending CID information stored in a local communications device to a remote communications device. Such methods may comprise: receiving an input signal, where the input signal may comprise an access code, a local input signal or remote input signal; addressing a remote communications device identified by an address code, where the address code may comprise a telephone number or paging telephone number; transmitting stored CID information to an addressed communications device, where the CID information may comprise CID messages or DTMF signals; outputting an OGM message for prompting input of an input signal; verifying that a received input signal matches a stored code, where the stored code may comprise an access code; addressing a remote communications device after verification that a received input signal matches a stored code, and where, again, the stored code may comprise an access code, and where the access code may in turn comprise a DTMF signal or signals; detecting a call termination signal; addressing a remote communications device after detection of a call termination signal; receiving a message entry tone; transmitting stored CID information after receipt of a message entry tone; transmitting a signal, such as a star tone signal, in between transmission of stored CID information; halting the transmission of CID information upon receipt of a second input signal, where the second input signal may comprise a pager full signal; storing CID messages in a message memory; detecting the presence of a full or partial CID message in a message memory; transmitting a full CID message upon detection of a partial CID message in a message memory; halting the transmission of the CID information upon the transmission of all of the stored CID information; receiving an address code which identifies a remote communications device; selecting the address code, associated with a received access code, from stored address codes. These inventive methods may be used with a local communication device which may comprise, for example, a telephone, communications central office, standalone CID device, TAD, PBX system, or a combination of one or more of these devices and a remote communications device which may comprise, for example, a paging device or paging system.
The present invention and its advantages can be best understood with reference to the drawings, detailed description of the preferred embodiments and claims that follow.

CID message retrieval methods and devices


A projection screen includes a polarized-light selective reflection layer having a cholesteric liquid crystalline structure, capable of selectively reflecting a specific polarized-light component; and a substrate that supports the polarized-light selective reflection layer. In the cholesteric liquid crystalline structure of the polarized-light selective reflection layer, the helical pitch on the side farther from the imaging-light-incident side is longer than that on the side closer to the imaging-light-incident side.

1. Field of the Invention
The present invention relates to a projection system in which imaging light emitted from a projector is projected on a projection screen to display thereon an image. More particularly, the present invention relates to a projection screen capable of sharply displaying an image and of providing high image visibility, and to a projection system comprising such a projection screen.
2. Background Art
A conventional projection system is usually as follows: imaging light emitted from a projector is projected on a projection screen, and viewers observe the light reflected from the projection screen as an image.
Typical examples of projection screens for use in such conventional projection systems include white-colored paper or cloth materials, and plastic films coated with inks that scatter white light. Besides, high-quality projection screens that comprise scattering layers containing beads, pearlescent pigments, or the like, capable of controlling the scattering of imaging light, are now commercially available.
Since projectors have become smaller in size and moderate in price in recent years, demand for household projectors such as projectors for family theaters is growing, and an increasing number of families are now enjoying projection systems. Household projection systems are often placed in living rooms or the like, which are usually so designed that environmental light such as sunlight and light from lighting fixtures come in abundantly. Therefore, projection screens for use in household projection systems are expected to show good image display performance even under bright environmental light.
However, the above-described conventional projection screens cannot show good image display performance under bright environmental light because they reflect not only imaging light but also environmental light such as sunlight and light from lighting fixtures.
In such a conventional projection system, differences in the intensity of light (imaging light) projected on a projection screen from a projector cause light and shade to form an image. For example, in the case where a white image on a black background is projected, the projected-light-striking part of the projection screen becomes white and the other part becomes black; thus, differences in brightness between white and black cause light and shade to form the desired image. In this case, in order to attain excellent image display, it is necessary to make the contrast between the white- and black-indication parts greater by making the white-indication part lighter and the black-indication part darker.
However, since the above-described conventional projection screen reflects both imaging light and environmental light such as sunlight and light from lighting fixtures without distinction, both the white- and black-indication parts get lighter, and differences in brightness between white and black become small. For this reason, the conventional projection screen cannot satisfactorily provide good image display unless the influence of environmental light such as sunlight and light from lighting fixtures on the projection screen is suppressed by using a means for shading a room, or by placing the projection screen in a dark environment.
Under these circumstances, studies have been made on projection screens capable of showing good image display performance even under bright environmental light. There have so far been proposed projection screens utilizing, for example, holograms or polarized-light-separating layers (see Japanese Laid-Open Patent Publications No. 107660/1993 (Patent Document 1) and No. 540445/2002 (Patent Document 2)).
Of these conventional projection screens, those ones using holograms have the advantage that the white-indication part can be made lighter if their light scattering effect is properly controlled, so that they can show relatively good image display performance even under bright environment light. However, holograms have wavelength selectivity but no polarization selectivity, so that the projection screens using holograms can display images only with limited sharpness. Moreover, it is difficult to produce large-sized projection screens by utilizing holograms because of production problems.
On the other hand, on the above-described conventional projection screens using polarized-light-separating layers, it is possible to make the white-indication part lighter and the black-indication part darker. Therefore, these projection screens can sharply display images even under bright environmental light as compared with the projection screens using holograms.
In connection with such projection screens using polarized-light-separating layers, we already proposed a projection screen comprising a cholesteric liquid crystalline, polarized-light selective reflection layer, capable of scattering, owing to structural non-uniformity in the cholesteric liquid crystalline structure, imaging light when reflecting it, without lowering image visibility (Japanese Patent Application No. 165687/2003).

Projection screen and projection system comprising the same


A nail polish bottle holder having a receptor well for the bottle and an elongate strap affixed to the well for securing the holder in a convenient place as for example a woman's wrist.

The present invention relates to supports and particularly to a support or holder for a bottle of nail polish.
Nail polish is ordinarily applied to the nails from a small bottle using a brush applicator affixed to the closure cap for the bottle. The bottle is small so that it is necessary to secure the bottle, as by holding it with one hand, as the applicator is dipped into the bottle. The bottle is then set aside as the applicator applies its fill of polish to a fingernail. These steps are repeated until all nails are polished.
The steps involved impose limits as to the conditions permitting proper nail polishing. Specifically, nail polishing is limited to a person being at rest preferably sitting and with a table or other handy surface for setting down the polish bottle as the hands are occupied with nail polishing.
In the hub-bub of daily routine with women on the go and so forth, it is often necessary if not desirable to deal with cosmetic applications while commuting to work, for example. Accordingly, the present invention provides a nail polish holder facilitating the application of nail polish on the go.


A series of pyridinyl tri-substituted benzamide derivatives of general structure ##STR1## wherein the symbols R.sup.1, R.sup.2, X and n are described in detail in the specification, are useful as anticonvulsants agents.

This application claims the benefit of U.S. provisional application 60/017,565, filed May 14, 1996.
The invention pertains to novel pyridinyl benzamide derivatives having drug and bio-affecting properties and to their preparation, pharmaceutical formulations and use. In particular, the invention concerns tri-substituted benzamides having a pyridine ring, with and without an alkyl linker, attached to the amide nitrogen. These compounds possess potent anticonvulsant properties that should make them useful in treating certain medical disorders.
The anticonvulsant drugs currently available in the United States have several shortcomings as therapeutic agents. About one of every three patients does not obtain significant relief from seizures and a number of side-effects accompany the therapeutic effects obtained. An underlying reason for the high incidence of side-effects is that most current anticonvulsant agents possess low therapeutic ratios. For this reason, new anticonvulsants, which may possess greater selectivity and less toxicity in a clinical population, are needed.
A large number of various benzamide derivatives are known and the use of many of them as medicinals has been disclosed.
A number of amino-substituted benzamides have been disclosed as anticonvulsant agents. In general, these disclosed compounds have structural formula 1, wherein Z is a substituted phenyl or phenylalkyl moiety. ##STR2##
For example, Robertson claims anticonvulsants, 2, in U.S. Pat. No. 4,684,748; ##STR3## and in U.S. Pat. No. 4,981,866, Beedle and Robertson claim the use of various mono-substituted benzamide derivatives, 3, as anticonvulsants. ##STR4## In formula 3, R.sup.1 can also be hydroxy, alkoxy and alkyl in addition to being substituted amino.
While a number of pyridinyl benzamide derivatives are known, they are not tri-substituted benzamides and have not been particularly disclosed for use as anticonvulsant agents. These known pyridinyl benzamide compounds conform to the general structural formula 4. In 4, R.sup.1 can be hydrogen, halogen, alkyl, alkoxy, amino and nitro; R.sup.2 is generally amino; ##STR5## and A is a chemical bond or an alkyl linking group.
As an example, Gadekar in U.S. Pat. No. 3,252,986 discloses a series of tranquilizers-muscle relaxants including compounds of formula 5. ##STR6##
Similarly, Wright and Tomcufcik describe a series of pyridinyl benzamides of formula 6 disclosed as cardioprotective agents and inhibitors of thromboxane synthetase. In 6, R is hydrogen, alkyl, ##STR7## alkoxy, or nitro; and n is 2 to 5.
Kruger, et al. in U.S. Pat. No. 4,093,734 disclose a subset of pyridinyl benzamides of formula 7 described as being useful anxiolytics, anticonvulsants, antiemetics, and antiulceragenics. ##STR8##
In 7, R.sup.1 is hydrogen or halogen and R.sup.2 is methyl, halogen or nitro.
Of less significance are disclosures of metaclopramide-type benzamide derivatives having antiemetic and gastroprokinetic properties. Monkovic, et al., are typical in disclosing a series of antiemetic tri-substituted benzamides, 8, in which ##STR9## R.sup.1 is a basic moiety such as --CH.sub.2).sub.n --NR.sup.7 R.sup.8 or ##STR10##
These foregoing references do not teach or suggest the specific novel pyridinyl tri-substituted benzamide derivatives of the present invention nor the anticonvulsant use of these compounds.

Anticonvulsant pyridinyl benzamide derivatives


Embodiments of the invention decrease bending vibrations and torsional vibrations of a voice coil generated by off-plane vibrational forces on the voice coil to reduce noise and to enable a large capacity. In one embodiment, a rotating disk type storage unit comprises a rotating disk recording medium, a head that moves radially relative to the rotating disk recording medium to perform recording or reproduction, a turnable actuator having mounted on one side thereof the head, and a voice coil motor to drive the actuator. The voice coil motor comprises a voice coil mounted on the other side end of the actuator, and a magnet arranged in opposition to the voice coil. A magnet outer periphery of the magnet disposed distant from an actuator turning center is formed to be arcuately concave in shape, and the concave-shaped outer periphery intersects the voice coil.

The present invention relates to a rotating disk type storage unit, and is suited to a rotating disk type storage unit, in which a voice coil motor drives an actuator mounting thereon a head.
A magnetic disk apparatus exemplary of a rotating disk type storage unit drives an actuator mounting thereon a magnetic head to thereby position the magnetic head that performs recording or reproduction of information on a magnetic disk. Used as a drive source for the actuator is a voice coil motor comprising a voice coil mounted on one end of the actuator, a magnet arranged in opposition to the voice coil, and a voice yoke member that forms a magnetic circuit. A thrust moment of the actuator is obtained from electric current applied to the voice coil of the voice coil motor and a magnetic circuit formed by the magnet and the voice yoke member.
In conventional magnetic disk apparatuses, there is disclosed a construction in JP-B-61-46901 (Patent Document 1), in which a thrust moment generated in a voice coil is made uniform in a range of movement of the voice coil.
With such magnetic disk apparatus, a length in a direction perpendicular to a direction of movement of the voice coil is made long from a central portion thereof to an edge thereof by forming a magnet such that its length perpendicular to the direction of movement of the voice coil is made long from a central portion thereof to an edge thereof. In such construction, a thrust moment tending to become small at ends of the range of movement of the voice coil is made uniform in the range of movement of the voice coil.

Rotating disk type storage unit with reduced vibration

Hitachi Global Storage Technologies Netherlands B.V.


An information reproducing device includes an information recording medium housing portion 8 for housing an information recording medium 7 that is detachably attached, a pickup 75 for reading information recorded at least on the information recording medium 7, and a pickup restrainer 94 for restraining a displacement that exceeds a normal operating range of the pickup 75, wherein the pickup restrainer 94 is constructed to displace in response to loading/unloading of the information recording medium 7 into/from the information recording medium housing portion 8.

1. Field of the Invention
The present invention relates to an information reproducing device that is capable of reproducing at least the information recorded on an information recording medium such as an optical disk, or the like,
2. Description of the Related Art
An amount of data is rapidly increased with the rapid development of the recent digital technology, and various information recording media have been developed to fit in with user's various applications. As examples of such information recording media, hard disk, optical disk, semiconductor memory, and the like can be listed.
Meanwhile, the information reproducing device, the personal computer, etc. employing these information recording media are in user's strong demand such that the user wishes to use the device not only in a room but also out of doors. As the device that assumes such mobile application, notebook mobile personal computer, mobile information terminal typified by PDA, cellular phone, mobile game device, digital still camera, digital video camera, and the like, for example, can be listed.
In case the handled contents in the mobile applications are mainly the still image or the text data, i.e., in case only a small recording capacity of the information recording medium is required, normally the semiconductor memory is often employed. The semiconductor memory possesses such merits that the memory has a small consumption power, the memory is resistant to a falling impact because no mechanism portion is provided, and the memory has a high data transfer speed. However, since the semiconductor memory has a high cost per memory capacity, such memory is unsuitable as the recording media for the contents such as the moving picture, and the like that need a large amount of data.
In contrast, the information recording medium using the optical dusk is excellent in superiority in cost per memory capacity in terms of exchangeability of the optical disk, random access performance, and productivity of the disk when manufactured as the read only media (ROM). In particular, the information recording medium using the optical disk is the mainstream of the information recording media used to record the contents such as the moving picture, and the like that need a large amount of data.
In the information reproducing device constructed to reproduce the information at least from the information recording medium using the optical dusk, a light emitted from a laser light source, for example, must be guided to the information recording medium via the optical member, an image is formed on a recording surface of the information recording medium, and it must be sensed based on a reflected light from a recording surface whether or not a minute pit formed on the recording surface in order of μm is present. Therefore, a very high alignment accuracy of a relative positional relationship between the optical member used to guide a light emitted from a light source to the information recording medium and form an image thereon and the information recording medium is needed.
Meanwhile, in the device that assumes such mobile application, the information reproducing device is always exposed to a risk of the strong impact applied when such device is dropped, or the like. In particular, the pickup is used guide a light from a light source to a recording surface of the information recording medium and transfer a reflected light from a recording surface. For this reason, a position of the pickup must be controlled at a high speed and with high precision such that the pickup is always kept at an equal distance to the recording surface of the information recording medium, as explained in detail later, and therefore the pickup has such a structure that its position can be displaced very easily (by a week force). Therefore, when a strong external force is applied to the information reproducing device by the falling impact, or the like, the pickup is displaced to exceed a normal range of position control, i.e., a normal operating range. In some cases the pickup itself, for example, is caused to hit other member and is damaged or the member such as the suspension wire, or the like for supporting the pickup, for example, suffers unrecoverable damage by the buckling deformation, or the like.
With respect to the information reproducing device in the prior art, the structures disclosed in JP-A-63-253544, JP-A-08-339564, and Patent Literature 3, for example, are known as the measure against the impact that the pickup receives.
In JP-A-63-253544, the moving portion (pickup) consisting of an objective lens, a focus coil, and a tracking coil and an objective lens driving unit having a protecting means for relaxing an impact force applied to the pickup from the outside are disclosed. According to Patent Literature 1, it is mentioned that, since a displacement of the pickup is restrained by covering the pickup with the protecting means made of a cover, a breakage of the pickup can be prevented previously even when the pickup gets an impact force caused by the collision with other mechanism elements.
In JP-A-08-339564, in the configuration that a focal length of a light source to the recording medium is adjusted by moving the objective lens supporting member (pickup), which holds the objective lens, along the optical axis direction of the objective lens, such a structure is disclosed that a displacement of the pickup is restrained by causing an engaging member provided to an outer side of the pickup to engage with a projection, or the like provided to a part of the focus coil contained in the pickup. According to Patent Literature 2, it is mentioned that there is no need to provide the cover, or the like to the pickup consequently and it can be prevented that the objective lens supporting member runs off the chassis or the objective lens collides with the recording surface of the information recording medium.
In JP-A-04-192169, such a structure is disclosed that an optical head housing portion for housing the optical head including the pickup is provided, the optical head is housed in the optical head housing portion when the information recording medium is not inserted into the device, and the optical head is fixed by a magnet in the optical head housing portion while a power supply is turned off. According to Patent Literature 3, it is mentioned that, since the optical head is housed and fixed to the optical head housing portion, a work to prevent a damage of the optical head can be omitted when a main body of the device is moved, for example, and also a dustproof effect can be achieved.
However, in the configuration shown in JP-A-63-253544, since the pickup is constructed such that it can be displaced at least in the inside of the protecting means made of the cover, the pickup when accepts the impact is displaced in the inside of the cover. However, the cover itself has an action to restrict a displacement of the pickup but has no action to absorb an impact force. In JP-A-63-253544, the case where a runaway of the optical head main body is caused by a driving motor in the magnetic circuit to move largely is taken up as the problem. In this case, since an impact force caused by the fall, or the like, for example, is quite larger than that caused by the runaway of the magnetic circuit, it is difficult to protect sufficiently the pickup itself and the peripheral mechanism of the pickup from the failure caused by such large impact force. A configuration that a buffer material is arranged further in the inside of the cover may be considered, but this configuration is unsuitable for the information reproducing device in the mobile application since reduction in size of the device becomes difficult because of an increase in size and weight of the cover.
In the case of the configuration shown in JP-A-08-339564, like the case in JP-A-63-253544, it is also difficult to protect sufficiently the pickup from the failure caused by a large impact force generated by the fall, or the like. Also, in the configuration shown in JP-A-08-339564, since a latching means is provided in a position that is away from a center of gravity of the pickup, a local stress is applied to the latching means when the pickup receives a strong impact. There is the problem about reliability.
According to the configuration shown in JP-A-04-192169, the impact that the optical head containing the pickup gets can be absorbed by optimizing the structure of the optical head housing portion to fit for a purpose, although not explicitly shown in Literature. Thus, it is expected that the pickup and its peripheral mechanism are protected from the failure caused by the large impact force generated by the fall, or the like. However, in JP-A-04-192169, since the optical head is moved horizontally in the optical head housing portion and housed, the optical head housing portion is arranged on the outside of the outermost periphery of the information recording medium such as the optical disk, or the like and thus a size of the device is increased. In particular, in the information reproducing device that assumes the mobile application, an increase in size of the device is unacceptable from a viewpoint of portability.


A system and method for timing image acquisitions provide an optical charge pulse to a sensor within an optical imaging system prior to image acquisitions by the optical imaging system. This optical charge pulse compensates for dark current discharge in the sensor.

Optical sources and sensors are included in a variety of optical imaging systems. In a typical optical imaging system, an optical source including one or more LEDs or other emitters illuminates a target, such as an imaging surface or navigation surface. The sensor detects reflected, scattered or transmitted light from the illuminated target. In an optical imaging system used for navigation, outputs from the sensor are processed to extract position, velocity, acceleration, or other motion parameters of the optical imaging system relative to the target. In other applications, the output from the sensor is processed to characterize features of the illuminated target.
FIG. 1 shows an exemplary control signal C for timing image acquisitions in a conventional optical imaging system (shown in FIG. 2). In this example, the optical source within the optical imaging system is turned "on" by a falling edge transition in the control signal C and turned "off" by a rising edge transition in the control signal. Image acquisitions are triggered to occur at the same falling edge transition that turns the optical source "on".
When the optical source is "off", the target is not illuminated and the sensor does not receive light. During this "off" time the sensor will typically discharge due to current leakage (referred to as "dark current") inherent within the devices used to implement the sensor, which can affect the sensitivity or transfer characteristics of the sensor.
In optical imaging systems where the sensor includes one or more CMOS detectors, photodiodes or other transducers, non-uniform discharge between these devices can result in non-uniform image sensitivity or artifacts in the images acquired when the sensor initially receives light from re-illumination of the target. In optical imaging systems used for navigation, dark current discharge of the sensor can result in cursor jump upon re-illumination of the target.
One approach avoids the dark current discharge of the sensor by illuminating the target continuously, so that the sensor continuously receives light. This approach has the obvious disadvantage of high power consumption, as constant illumination of the target translates to the optical source being on continuously. In a portable optical imaging system, such as an optical mouse for a computer, this high power consumption can lead to unacceptably low battery life. Accordingly, there is a need for an alternative way to accommodate for dark current discharge in the sensor within an optical imaging system.

Image acquisition timing system and method


A vehicular power inverter connector assembly is provided. The assembly includes a housing, a plurality of first engagement formations on the housing shaped to mate with a plurality of inverter engagement formations on a vehicular power inverter, a plurality of second engagement formations on the housing shaped to mate with a plurality motor engagement formations on a vehicular motor, and a plurality of current sensors connected to the housing and configured to detect current flowing between the vehicular power inverter and the vehicular motor.

In recent years, advances in technology, as well as ever evolving tastes in style, have led to substantial changes in the techniques used to design and build automobiles. One of the changes involves the complexity of the various electrical systems within automobiles. As a result, electrical systems in automobiles, especially hybrid vehicles, are using an ever increasing amount of electrical power.
Many of the electrical components, such as electric motors, used in such vehicles receive electrical power from alternating current (AC) power supplies. However, the power sources (i.e., batteries) used in such applications only provide direct current (DC) power. Thus, devices known as power inverters are used to convert the DC power to AC power.
The current flowing from the power inverter to the motor, or other electric component, is typically monitored to ensure proper operation. Conventional power inverters utilize one or more wiring harnesses and a bundle a wires to connect the power inverter to a current sensor, and in turn connect the current sensor to the motor. The wiring harnesses and external current sensor increase the overall size of the power inverter, as well as add to the complexity of installing and servicing the power inverter. Additionally, because of the large amounts of power involved, high performance wiring harnesses are typically used, which significantly adds to the costs of manufacturing the vehicle.
Accordingly, it is desirable to provide a power inverter connector with an integrated current sensor that reduces the size and complexity of the power inverter. In addition, it is desirable to provide a power inverter assembly that eliminates the need for the wiring harnesses. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.

Power inverter connector having integrated current sensors


A curtain wave forming mechanism is constituted of curtain runners and a curtain hook attached to each curtain runner and hanging a curtain. The curtain hook is a separate body from a curtain tape and has a flat plate-like body section inserted into a hook insertion hole section of the curtain tape perpendicular to the length direction of a curtain rail, a foot section bent upward at the lower end central part of the body section and hooked to the hook insertion hole section, a shaft section extending from the upper central part of the body section, and a head section for insertion, formed on the head of the shaft section. A curtain runner has a body running in the curtain rail, a leg section hanging from the curtain rail, a hollow-cylindrical body supported at the leg section so as to be rotatable about the vertical axis of the leg section, and a bearing section for an insertion hook, supported at the hollow-cylindrical body.

1. Field of the Invention
The present invention relates to a curtain wave forming mechanism, which comprises a plurality of curtain runners installed in a curtain rail and curtain hooks attached to the respective curtain runners for hanging a curtain.
2. Description of Background Art
A curtain is expected to form a naturally elegant curtain wave when it is suspended by the use of flat wide curtain hooks each being vertically rotatably attached to a curtain runner, because the curtain hooks rotate integrally with the curtain without preventing the curtain from forming a curtain wave. In a curtain rail in which the pitch (maximum interval) of curtain runners is determined, the curtain forms a curtain wave of which the nodes are identical in position with the respective curtain runners, each wave cycle having a contour length equal to twice the pitch of curtain hooks and a height defined by the pitch of the curtain hooks.
It has been disclosed in JP Y 5-22145 that flat wide curtain hooks are used for making a curtain to form a curtain wave. The curtain hooks are integral with a curtain tape and fixed onto the surface of the curtain tape at a given distance from one another, each curtain hook having a flat wide body section and an insertion hook section extending from the upper part of the body section. The insertion-type hooks have their flat wide body sections fixed to the surface of the curtain tape at a given distance from one another and their hook sections vertically rotatably lowered from the respective curtain runners, so that the curtain forms a naturally elegant wave.
However, the conventional flat wide insertion-type hook has a problem that, in the curtain rail in which the pitch (maximum interval) of curtain runners is determined, it is impossible to adjust the height of wave without exchanging the curtain tape, because the hooks are integral with the curtain tape. Furthermore, it is another problem that the conventional curtain runner is unable to keep the direction of the curtain hook with the result that the curtain wave is apt to fall into disorder in the lead and tail portions of the curtain. It is a further problem that the conventional flat wide curtain hook with the insertion hook section is unfit for an ordinary ring-type curtain runner.
Reference: JP Y 5-22145


A magnetic encoder, which comprises a stainless steel sheet; and an under coat adhesive containing epoxy resin and organopolysiloxane, a top coat adhesive containing phenol resin, or phenol resin and epoxy resin, and a rubber magnet, as successively laid one upon another on the stainless steel sheet, has distinguished water resistance and saline water resistance, and thus can be effectively used particularly as a magnetic encoder in wheel speed sensors.

Magnetic encoders using a rubber magnet are excellent for detection of revolution rate at a low speed and recently have been widely used in wheel speed sensors, etc. Wheel speed sensors are used in the neighborhood position of wheel, requiring good water resistance and a saline water resistance. The magnetic encoder using a rubber magnet comprises a stainless steel sheet, a rubber magnet, and an adhesive for bonding these two. Water resistance tests show that peeling occurred at the interface between the stainless steel sheet and the adhesive of the magnetic encoder, and the water resistance of the adhesive as well as the rubber magnet itself is regarded as very important.
For the adhesive layer for the water resistance purpose, epoxy resin is usually used, but owing to poor adhesion to the stainless steel sheet, the epoxy resin is not used alone in case of the stainless steel sheet. In case of a single adhesive layer, a phenol resin-based adhesive, a silane-based adhesive, an epoxy resin/silane-based adhesive, or the like is used. In case of two adhesive layers, the afore-mentioned phenol resin-based adhesive, a phenol resin/halogenated polymer-bases adhesive, a phenol resin/epoxy resin-based adhesive, or the like is used as an under coat. However, even if these under coat adhesives are used in combination with various top coat adhesives, no statisfactory water resistance can be obtained in severe circumstances such as saline water spraying.


A cylinder head of an internal combustion engine is fitted with rocker arms. Camshafts are disposed so that the rocker arms and cams will be brought into contact with each other. The camshafts are rotatably supported by lower bearings, which supports the camshafts from below, and by upper bearings integrated with a head cover. The head cover is provided with visual observation windows that make it possible to see valve system parts through the head cover. A visual observation window covers for covering the visual observation windows are fixed to the head cover.

1. Field of the Invention
The present invention relates to a camshaft support structure for an internal combustion engine, and, in particular, to a camshaft support structure suitable for supporting camshafts in an internal combustion engine that is mounted on a vehicle.
2. Description of the Related Art
As described in Japanese Patent Application Publication No. 7-166956 (JP-A-7-166956), for example, a camshaft support structure in which upper bearings are integrated with a head cover is available. This conventional support structure is provided with a lower bearing that is paired with each upper bearing. The upper bearing and the lower bearing are both formed so as to have semicircular concave surfaces, and support camshafts by being fixed in a state where the upper and lower bearings are opposed to each other.
Cams for opening intake valves or exhaust valves are fixed to the camshaft. The intake valves and the exhaust valves are opened by being pushed by cam noses as the camshafts rotate. When the cam nose pushes and opens the intake valve or the exhaust valve, the reaction force is applied to the camshaft. The reaction force acts in a direction such that the camshaft is pressed against the upper bearings. For this reason, the upper bearings require higher rigidity than the lower bearings.
With the above conventional support structure, it is possible to give high rigidity to the upper bearings by integrating them with the head cover. Such rigidity makes it possible to support the camshaft with high accuracy owing to the sufficiently high rigidity.
In order to obtain the above conventional support structure, the assembly procedure as described below is necessarily taken. Specifically, in order to realize this structure, a cylinder head is first fitted with the intake valves and the exhaust valves. Next, rocker arms are placed on the intake valves and the exhaust valves. The rocker arms are the members for transmitting the pushing force of the cams to valve elements.
In another step than the above step, camshafts are fitted to the head cover. That is, in a state where the camshafts are placed on the upper bearings in the head cover, the lower bearings are fixed to the upper bearings. As a result, the camshafts are rotatably held by the head cover.
After the above step, the head cover is fixed to the cylinder head with the camshafts held by the head cover. In this step, it is necessary that the camshaft is disposed so that the rocker arms are properly sandwiched between the cams and the valve elements.
However, normally the rocker arms are merely put on the valve elements until they are held down by the camshafts. For this reason, the rocker arms are prone to fall off when the head cover holding the camshafts is fixed to the cylinder head. In order to prevent such falling off, it is preferable to be able to see the rocker arms when the head cover is fixed to the cylinder head. Moreover, in order to check the condition of the valve system, it is preferable to be able to easily see the condition of the rocker arms even after the internal combustion engine has been properly assembled.
However, with regard to the above conventional support structure, when the head cover is fixed to the cylinder head, it is very difficult to see the rocker arms that are located inside the head cover. In addition, it is necessary to remove the head cover in order to see the condition of the rocker arms; and it is impossible to see the rocker arms in a state where the assembly is completed. In this respect, the above conventional support structure is not always preferable from the viewpoint of productivity and easiness of maintenance/inspection.
The valve train of the internal combustion engine, especially the parts around the cams are important elements to allow the internal combustion engine to operate properly. For this reason, it is preferable to be able to check whether the cams are properly installed, or whether foreign matter is caught around the cams, for example, through visual inspection at the time of the maintenance/inspection of the internal combustion engine.
However, because the upper bearings are integrated with the head cover in the above conventional support structure, it is impossible to remove the head cover, leaving the camshafts properly held in the internal combustion engine. Accordingly, if this support structure is used, it is impossible to see the cams, leaving the camshafts held. In this respect, the above conventional support structure is not always ideal from the viewpoint of productivity in manufacturing the internal combustion engine, and the workability of the maintenance/inspection.

Camshaft support structure for internal combustion engine


A signal transmission apparatus in a Double Orthogonal Frequency Division Multiplexing (DOFDM)/Double Orthogonal Frequency Division Multiple Access (DOFMA) communication system generates a first signal by performing row-wised Orthogonal Frequency Division Multiplexing (OFDM) on M sub-samples for each of N sub-carriers, generates a second signal by performing column-wised OFDM on the first signal generated for each of the N sub-carriers, and transmits the second signal to a signal reception apparatus. Here, N denotes a number of sub-carriers used in the DOFDM/DOFDMA communication system, and M denotes an integer greater than or equal to 1.

1. Field of the Invention
The present invention relates to an apparatus and method for transmitting/receiving and relaying signals in a communication system using Double Orthogonal Frequency Division Multiplexing (DOFDM)/Double Orthogonal Frequency Division Multiple Access (DOFDMA) (hereinafter referred to as "DOFDM/DOFDMA communication system").
2. Description of the Related Art
Next-generation communication systems have developed to provide a variety of high-speed, high-capacity services to Mobile Stations (MSs). Particularly, the next-generation communication systems use Orthogonal Frequency Division Multiplexing (OFDM)/Orthogonal Frequency Division Multiple Access (OFDMA) to offer the high-speed, high-capacity services. A typical example of the next-generation communication systems using OFDM/OFDMA may include an Institute of Electrical and Electronics Engineers (IEEE) 802.16 communication system, a Mobile Worldwide Interoperability for Microwave Access (WiMAX) communication system, an IEEE 802.11 communication system and the like. The Mobile WiMAX communication system is a communication system based on the IEEE 802.16 communication system, and the IEEE 802.16 communication system represents a communication system using the IEEE 802.16 standard. In addition, the next-generation communication systems actively consider using a relay scheme, especially a cooperative relay scheme, to expand cell coverage, increase data throughput, and increase channel capacity.
Meanwhile, the above-described next-generation communication systems require broad-spectrum resources to offer the high-speed, high-capacity services. However, when the broad-spectrum resources are used, a fading effect becomes significant in a wireless channel due to multipath propagation, and an influence of frequency selective fading occurs even in an actual frequency band.
In this case, therefore, a frequency selective fading channel can be divided into a plurality of frequency flat fading channels using OFDM/OFDMA. Here, a communication system using OFDM/OFDMA will be referred to as an OFDM/OFDMA communication system. In the OFDM/OFDMA communication system, all multi-path signals of a signal transmitted by a signal transmission apparatus should be received within a period of a Cyclic Prefix (CP) at a signal reception apparatus to guarantee orthogonality between sub-carriers. If the signal reception apparatus fails to receive all multi-path signals of the transmission signal within the CP period, Inter-Carrier Interference (ICI) occurs in a signal demodulated by the signal reception apparatus, and the ICI makes the signal reception apparatus difficult to estimate the transmission signal.
Particularly, when the OFDM/OFDMA communication system uses the cooperative relay scheme, a signal received at the signal reception apparatus via a Relay Station (RS) may have a long delay time, compared with a signal received at the signal reception apparatus over a direct path between the signal transmission apparatus and the signal reception apparatus. Here, the time required when the signal transmitted by the signal transmission apparatus is received at the signal reception apparatus via the direct path will be called a 'direct-delivery delay time', while the time required when the signal transmitted by the signal transmission apparatus is received at the signal reception apparatus via the RS will be called a 'relay-delivery delay time'. As described above, a signal receiving delay in the OFDM/OFDMA communication system causes ICI, which deteriorates estimation performance for the transmission signal. Thus, deterioration of signal estimation performance due to the signal receiving delay may become more significant when the OFDM/OFDMA communication system uses the cooperative relay scheme. That is, ICI occurrence probability increases because of the long relay-delivery delay time compared with the direct-delivery delay time, and deterioration of signal estimation performance due to the signal receiving delay may become more significant when the OFDM/OFDMA communication system employs the cooperative relay scheme.
Therefore, there is a need for an apparatus and method for transmitting/receiving and estimating signals such that no ICI may occur in the communication system using a broad spectrum.

Apparatus and method for transmitting/receiving and relaying signal in a communication system using DOFDM/DOFDMA

University-Industry Cooperation Foundation of Korea Aerospace University