An external cavity laser apparatus and method wherein wavelength or channel selection is carried independently from adjustment of external cavity optical path length. The apparatus comprises a wavelength or channel selector tuner and an external cavity tuner, wherein the wavelength tuner is uncoupled from the external cavity tuner. The tuning mechanisms for wavelength selection and cavity optical path length are configured to operate independently or orthogonally with respect to each other. The wavelength tuner may operate according to a first, channel selection signal, while the external cavity tuner operates according to a second, external cavity adjustment signal. The wavelength tuner and external cavity tuner may operate under the control of the same, or of separate controllers. The channel selection signal may be derived from a look-up table of adjustment parameter data accessed by a controller, and the external cavity adjustment signal may be derived from an error signal from a detector configured to measure external cavity loss.

Fiber optic telecommunications are continually subject to demand for increased bandwidth. One way that bandwidth expansion has been accomplished is through dense wavelength division multiplexing (DWDM) wherein multiple separate data streams exist concurrently in a single optical fiber, with modulation of each data stream occurring on a different channel. Each data stream is modulated onto the output beam of a corresponding semiconductor transmitter laser operating at a specific channel wavelength, and the modulated outputs from the semiconductor lasers are combined onto a single fiber for transmission in their respective channels. The International Telecommunications Union (ITU) presently requires channel separations of approximately 0.4 nanometers, or about 50 GHz. This channel separation allows up to 128 channels to be carried by a single fiber within the bandwidth range of currently available fibers and fiber amplifiers. Improvements in fiber technology together with the ever-increasing demand for greater bandwidth will likely result in smaller channel separation in the future.
The drive towards greater bandwidth has led to use of precision wavelength-specific DWDM devices that require careful adjustment and calibration according to the narrow transmission channel spacings. Continuously tunable lasers have been developed to aid in the test and measurement of these sophisticated devices. Tunable lasers of this sort typically utilize a tuning element, such as a pivotally adjustable grating within an external cavity, in order to generate an adjustable wavelength sweep in the laser output that can be used in the characterization of precision WDM components.
One problem which can arise with such tunable lasers is "mode-hopping" wherein the laser changes frequency discontinuously to a different longitudinal mode. When used as a telecommunication transmitter, these mode hops will cause transmission errors in the modulated data stream. One approach taken for designing tunable lasers is to use a relatively long cavity with finely spaced modes, and tune the laser in a "quasi-continuous" manner, mode hopping between the finely spaced modes. Inherent to this design is the fact that a mode hop occurs when the wavelength of operation is changed. The modes themselves are not controlled, and thus the wavelength of operation cannot be precisely tuned within the interval of a mode hop.
Another approach to tunable lasers is "mode hop free" tuning where the cavity length is synchronously changed with the wavelength tuning mechanism to keep the laser operating in the same longitudinal mode while tuning. This approach can potentially avoid the mode hopping problem and can tune to all wavelength but the constraint of synchronous adjustment makes the implementation of this design difficult.
The increasing use of re-configurable optical network architectures has recently led to the use of tunable external cavity lasers as optical communication transmitters. The tunable external cavity lasers used for telecommunication have been configured in generally the same manners as the tunable lasers used for test and measurement purposes, with the tuning of the grating being coupled to tuning of the external cavity to provide mode hop-free tuning in the laser wavelength output.
This type of mode hop-free tuning, however, has proved to be non-optimal for stable tuning to narrowly spaced transmission bands, as is required for high bandwidth DWDM systems. Mode hop-free tuning is often difficult to implement and in many cases involves a time-consuming location of a specific or "magic" pivot point to provide a specific rotation/translation relationship for tuning the grating and optical cavity length.
More particularly, the design goal of mode hop free tuning is to couple the wavelength selection filter, which selects one of the many possible longitudinal modes of the laser, with changes in the effective cavity length of the cavity, which determines the wavelength of the longitudinal modes, and thus the exact wavelength of operation. When the coupling between the cavity length and wavelength filtering is not precise, mode hops may still occur along the tuning curve, albeit at fewer points than if there was no coupling. More particularly, the coupling of the wavelength filter to the cavity modes precludes adjusting the wavelength filter without coupling this change directly into the cavity length and wavelength of operation. Although a mode hop free tuning architecture may be a good design choice for a test and measurement laser, it is not necessarily an optimal design choice for a tunable DWDM transmitter source.
When tuned, a DWDM transmitter must cease emission at the original wavelength of operation and then recommence emission at a second, precisely defined, wavelength. In general, emission at any other wavelength cannot be sent into the system since this may cause crosstalk between the channel being tuned and other transmission channels. One method for tuning is to mode hop the laser directly to the target wavelength. It is more practical to tune with the laser powered down, shuttered, filtered, or otherwise guaranteed to avoid other wavelengths during tuning, where these precautions may be taken at the system level or at the source. With these precautions, the precise mode hop behavior of the laser during tuning between channels is not important. It is important that the target wavelength is precisely achieved. The effective cavity length, which determines the exact wavelength of operation, must be precisely controlled. Only after tuning and transmission into the system commences must mode hopping, which causes amplitude and frequency changes in the source, be avoided.
In some DWDM systems, the channel frequencies are adjusted during operation to maximize system capacity at acceptable bit error rate. Telecommunication sources must operate over a large temperature range, with −5° C. to 70° C. being typical, and the effect this temperature has on effective cavity length, filter characteristics, and the general state of the laser, must be countered. The operation characteristics of thermal compensation and fine frequency control are similar and lead to the requirement that a telecommunication transmitter have precise control of cavity length and the wavelength filtering element. In view of these design considerations, a mode hop free tuning approach does not confer the same advantages in DWDM source applications as it does in a test and measurement application. There is a need for a tunable laser source for DWDM applications which has independent fine control of the wavelength filtering element and cavity length but is not restricted to avoiding mode hop behavior when coarsely tuning.

External cavity laser method and apparatus with orthogonal tuning of laser wavelength and cavity optical path length


A method and apparatus for recording multiple channels of digital audio data onto one-half inch tape using a rotary head recorder. The tape format includes sector spaces and a write timing sector to provide reduced susceptibility to errors arising from head misalignment, provides improved punch-in and punch-out capabilities using overdub identification values recorded within each channel of audio information, and provides a unique time code word that facilitates accurate high-speed scan and search operations, as well as multiple device synchronization. Each pair of audio tracks terminates with a write timing sector that serves as an absolute location marker for the rotary head, and allows the digital audio system to determine precise head location with respect to the tape.

1. Field of the Invention
The invention relates to the field of digital audio recording and, more specifically, to a method and apparatus for recording multiple tracks of digital audio information onto magnetic tape using a rotary magnetic head, with high dropout immunity, reduced susceptibility to head misalignment and improved ability to scan at high linear tape speeds.
2. Description of the Prior Art
A full fidelity digital audio recorder requires a 1 MHz storage bandwidth per recorded audio channel. Because a rotary head digital recorder has a wide bandwidth, it is an ideal storage device for digital audio signals. Using digital procesing techniques, an audio signal is converted into a digital format and recorded onto a magnetic medium. Upon playback, the digital signal is converted first to a corrected digital audio bit stream and then to an analog waveform.
The high bandwidth required to effectively record a digital audio signal necessitates a high tape speed. Rotary head recorders achieve a high bandwidth as a result of high relative heat-to-tape speed. Media recorded using a rotary head can achieve 60,000 flux transitions/inch, about the same as stationary head recording, but track density may reach 2,000 tracks/inch, or about 10 times that of stationary head recording. Data transfer rates of 1 to 4 Mbytes/second are obtained, as the rotary head records the digital audio data onto the tape using a technique called helical scanning. In helical scanning, two or more electromagnetic heads are positioned on a head cylinder. The head cylinder is rotated at a speed (e.g., 3,000 revolutions/minute) that allows the use of a lower tape speed while still maintaining a high relative head-to-tape speed. As shown in FIG. 1, the tape is helically wrapped around a portion of the cylindrical drum.
Helical scanning records diagonally aligned tracks onto the tape. Because the tape is guided past the heads at an angle, each recorded track is placed diagonally across the tape width. FIG. 2 illustrates the diagonal tracks created by helical scanning. Each of the two heads on the cylinder alternately lays down a track 201 onto the tape 202. Each pair of tracks 203 represents a specified amount of audio signal. The tracks are recorded side by side without any space separation.
When re-recording a signal onto digital tape, the new signal is recorded over the signal previously recorded on the tape. The accumulation of debris on the tape can cause a media dropout, or recording omission, so that the new data is not properly recorded and old data is therefore not completely erased. After the re-recording operation is performed, and the debris is removed from the surface of the magnetic tape, the read head may detect old data on the track at the point where the dropout occurred. It is difficult to detect, using standard detection means, such an erasing or recording omission. When the new data is reproduced along with the old data in a digital audio system, abnormal sounds may be generated due to the unerased old data.
In professional digital audio applications, in addition to being able to record several channels on a single tape, it is often desirable to be able to selectively re-record individual channels. For example, a guitarist, after reviewing a studio session recorded with other musicians, may want to re-record a portion of his guitar solo, while leaving the rest of the recording unaltered. Additionally, possibly because he is no longer at the original studio, the guitarist may want to re-record using a different digital audio recorder than was originally used. Selectively re-recording a portion of a single channel (called "punching-in") is difficult because of the high density of data recorded using a rotary head, and because some dissimilarities in head alignment may exist between the two machines. If the new guitar solo is not precisely re-recorded over every group of bits of the old solo on the tape, the digial audio system is not able to differentiate between the old and new data on the tape. Consequently, during playback, the listener will hear portions of the old solo mixed with portions of the new solo.
During normal operation, the rotary head detects all of the information stored on the magnetic tape. However, in a high-speed scan, or "shuttle" mode, the linear tape speed is increased while the rotational speed of the rotary head is kept constant. It is desirable to record the digital information onto the magnetic tape so that the digital audio system can accurately locate and monitor specific audio portions of the tape during both normal and shuttle operation. For example, such a tape format is particularly suited to synchronizing applications, where one or more slave recorders are synchronized with a master recorder, and the slave and master tapes are operated with a precise timing relationship to one another at both normal operating speeds and higher scanning speeds. For an example of one possible synchronizing system, see the invention described in co-pending U.S. application Ser. No. 07/822,464, entitled "Method For Synchronizing Digital Audio Tape Recorders," filed Jan. 17, 1992, and assigned to the Assignee of the present invention.
Disadvantages of rotary head designs arise mainly in professional applications. Razor blade editing is not possible with a rotary head data track as it is with a stationary head recorder. Therefore, rotary head designs require electronic editing. Expensive and complex digital audio editors are required to perform electronic editing in the prior art. Another disadvantage of rotary head design stems from the multiplexing of channels: it is difficult to record and replay separate channels simultaneously. Similarly, punch-in/out is not readily feasible. Punch in/out describes a procedure whereby as a channel is played back it is placed in the record mode at a certain point in the music to record new material, then taken out of the record mode at the end of the new passage to be recorded.
Rotary head designs are used for some 2-track professional applications. Nevertheless, professional audio applications that require electronic editing and multi-track and synchronous recording capabilities have typically retained the stationary head design for digital audio recording.
One rotary head transport system optimized for digital audio is the Digital Audio Tape (DAT) cassette format. The standard DAT system uses tape that is 3.81 mm wide capable of recording up to two hours of 2 channel digital audio onto a single cassette. The DAT system also supports 4 channel recording of 12-bit nonlinear quantized audio data using a 32 kHz sampling rate.
One prior art digital audio rotary head system is capable of recording 12 tracks of digital audio onto a specially designed 8 mm cassette. Because of the relatively small tape width, however, the prior art system's high bit density renders it highly susceptible to errors due to media dropouts. Further, the system is only capable of recording approximately 15 minutes of digital audio information per cassette.
Tape cassettes that contain 8 mm wide tape are of fairly good quality and are generally available, but cannot accommodate many tracks without a significant decrease in total playing time. The same holds true for the 3.81 mm R-DAT tape. One-half inch wide tape is superior in that it is widely available and can accommodate multiple channels of digital audio without sacrificing playing time.
The use of a rotary head design for digital audio recorders offers the opportunity to achieve the high bandwidth required for digital audio storage. The narrow track width and high tape-to-head speed of rotary head designs yield high recording density and low tape consumption. A digital audio tape format for use with one-half inch tape is an attractive alternative to prior art systems that use 8 mm or R-DAT (3.81 mm) tape. One-half inch tape is wider, allowing more data to be recorded per linear inch without increasing dropout susceptibility. Further, standard one-half inch cassettes provide longer playing times than standard 8 mm or R-DAT tapes. Also, mass production of one-half inch tape allows it to be manufactured at low cost, making a relatively sophisticated storage medium available to both consumers and professionals. It is therefore desirable to design a tape format that can be used to record multiple channels of digital audio information on one-half inch tape.

Format for recording digital audio onto magnetic tape with enhanced editing and error correction capability


A three-axis stabilized spacecraft is subject to a velocity change in a desired direction by a thruster. Unavoidable alignment errors cause a body torque, which tends to slew the body away from the attitude which orients the thrust axis in the direction. The attitude control system eventually corrects the attitude, but the thrust during the attitude transient results in an error in the direction of the velocity change. This error in the direction accumulates during the attitude transient. When the attitude transient passes, no further pointing error occurs. A control system, operating without an accelerometer, determines the total error accumulated during the attitude transient, and processes the error signal to generate a supplemental torque demand signal, which is added to the torque demand signal produced by the attitude control system, to cause an oppositely-directed attitude transient to thereby cancel the original velocity change direction error.

Spacecraft are often launched on a booster which places the spacecraft in an orbit which is lower than the desired orbit. In order for a spacecraft to achieve the desired orbit, it may be necessary to operate a velocity change (delta-V or .DELTA.V) thruster mounted on the spacecraft body.
When spin-stabilized spacecraft are accelerated by a velocity change thruster such as a liquid apogee thruster (LAE), the spinning spacecraft body provides gyroscopic stiffness which tends to reduce deviations of the longitudinal axis of the body from the desired pointing direction. In this context, the pointing direction is the direction in which the velocity change is desired. Three-axis stabilized spacecraft, however, do not rely on spin stabilization, and are stabilized by the operation of an attitude control system, which uses controllable torquers to rotate the body about the three axes of control. These axes are normally designated as the yaw, roll, and pitch axes.
When a spacecraft is fabricated, a great deal of attention is paid to aligning the thrust axes of the various thrusters relative to the center of mass of the spacecraft in a manner which results, when each thruster is fired, in the desired torque. In the case of attitude control thrusters, the desired torques are those around the three principal axes. In the case of the velocity change thruster, the desired torque is zero around each of the three body axes. That is, the velocity change thruster desirably imparts only a velocity change in the direction of its axis of thrust, and ideally does not impart a torque to the spacecraft body. In order to minimize the torques which the velocity change thruster imparts to the spacecraft body, its thrust axis is aligned as closely as possible with the center of mass of the spacecraft body.
In reality, it is not possible to determine the exact location of the center of mass of the spacecraft body, or to align the thrust axis of the velocity change thruster therewith. It is also difficult to determine the exact axis of thrust of the thruster. Consequently, operation of the velocity change thruster always results in some unwanted torques, which tend to rotate the spacecraft away from the desired pointing direction.
The attitude of a three-axis stabilized spacecraft is controlled by its attitude control system, as by operating momentum or reaction wheels, by magnetic torquing, or by operating attitude control thrusters. The disturbance torques occasioned by operation of the velocity change thruster are opposed by the torques produced by the attitude control system. However, due to the finite bandwidth of the attitude control system, there is some delay between the torque occasioned by the velocity change thruster and the opposing correction torque produced by the attitude control system. This delay results in a pointing error, which exists or continues until the attitude control system applies control to fully counteract the disturbance and realign the spacecraft with the desired pointing directions. During the interval between initiation of operation of the velocity S change thruster and the stabilization of the attitude control system, a component of velocity change occurs in an unwanted direction, which is not corrected by the attitude control system.
Improved spacecraft control systems are desired.

Delta-V targeting system for three-axis controlled spacecraft


The invention is directed to highly crystalline, frit-sintered glass-ceramic compositions having a coefficient of thermal expansion in the range of 85-115×10−7° C. The primary crystal phases of the glass-ceramics of the invention possess a cyclosilicate structure. The glass-ceramic of the invention are useful as metal-to-metal, metal-to-ceramic and ceramic-to-ceramic sealing agents, and also as high-performance coating for metals and ceramics. In their broadest composition the glass-ceramic contain, in weight percent, 30-55% SiO2, 5-40% CaO, 0-50% BaO, 0.1-10% Al2O3, and 0-40% SrO, wherein the sum of CaO+BaO+SrO is in the range of 35-65 wt. %. Optionally, the glass-ceramic compositions may contain at least one from the group of >0-15 wt. % MgO and >0-10 wt. % ZnO. Also optionally, the glass ceramic compositions may contain >0-10 wt. % of at least one transition metal or rare earth metal oxide.

Glass-ceramics are polycrystalline materials formed by controlled crystallization of a precursor glass article. A glass-ceramic may be prepared by exposing a glass monolith to a thermal treatment for conversion to a crystalline state. This is referred to as "internal nucleation" or a "bulk" or "monolith glass-ceramic forming process."
Glass-ceramics may also be prepared by firing glass frits in what is referred to as powder processing methods. A glass is reduced to a powder state, formed to a desired shape, fired and crystallized to a glass-ceramic state. In this process, the relict surfaces of the glass grains serve as nucleating sites for the crystal phases. The glass composition, particle size, and processing conditions are chosen such that the glass softens prior to crystallization and undergoes viscous sintering to maximum density just before the crystallization process is completed. Shape forming methods may include but are not limited to extrusion, slip casting, tape casting, spray drying, and isostatic pressing.
Sintered glass-ceramic materials have properties that may make them suitable for many uses. Examples of such uses include high strength structural composites; sealing agents to effect metal-to-metal, metal-to-ceramic and ceramic-to-ceramic seals, including hermetic glass-to-metal electrical feed-through seals; and as sealing agent in microreactors and bioassay equipment. While various materials have been used as sealing agents, for example, epoxies and cements among others, improvements in this area are needed. The present invention discloses glass-ceramic materials that can be used as sealing materials, and also as high temperature coating, for metals and ceramics.
The present invention is directed to novel compositions suitable for forming glass-ceramic materials that may be used in a variety of applications. In particular, the glass-ceramic materials of the invention can be used as sealing agents and as high performance coating for metals, metal alloys and ceramics.

This patent is subject to a terminal disclaimer.

High thermal expansion cyclosilicate glass-ceramics


In an ink-jet printing apparatus, upon turning on the power source of the printing apparatus, a stirring operation of ink in the main tank is performed for a given period of time, and during subsequent printing operation, the stirring operation in the main tank is performed for the given period at every predetermined elapsed time period. By this, the printing operation for a long period can be performed employing ink having a water insoluble dye without causing a problem of admixing of bubble or so forth caused by stirring of the ink in the main tank.

1. Field of the Invention
The present invention relates generally to an ink-jet printing apparatus. More specifically, the invention relates to an ink-jet textile printing apparatus for performing printing on a cloth or so forth.
2. Description of the Related Art
As typical method for performing printing on a cloth, a wall paper and so forth, a screen textile printing method for performing direct printing on the cloth and so forth employs a silk screen printing plate. In this method, with respect to an original image, at first, the silk screen printing plates are prepared for respective colors used in the original image. Then, the silk screen printing plate is loaded on a screen textile printing apparatus to perform printing by directly transferring an ink to the cloth or so forth through a mesh of the silk screen printing plate.
However, in such screen textile printing method, a huge amount of process steps and working days are required for preliminarily preparing the silk screen printing plates. Further operation is required for blending of inks for respective colors, and registering of the silk screen printing plate per each color. In addition, the screen textile printing apparatus per se is bulky, and the size of the apparatus is increased in proportion to number of colors to be used to require a substantial space for installation. Also, a space for storing the silk screen printing plates become necessary.
Therefore, it has been proposed an ink-jet textile printing system for performing printing directly on a printing medium, such as the cloth, the wall paper and so forth. The ink-jet textile printing system is to eject a fine ink droplet through ejection openings of an ink-jet head to perform printing an image or so forth by forming ink dots on the printing medium. The ink-jet textile printing system has many advantages such that there is not required the screen printing plate which has been required in a conventional screen textile printing system, and process steps and working days for forming the image on the cloth significantly shorten. Furthermore, the ink-jet textile printing system is advantageous for capability of down-sizing of the apparatus. In addition, since printing information for printing can be stored in various storage media, such as tape, flexible disk, optical disk and so forth, the ink-jet textile printing system is superior in safekeeping and storage of the printing information. Furthermore, the ink-jet textile printing system is advantageous in easiness of processing of the printing information, such as changing of color, layout, expansion and contraction of the image and so forth.
On the other hand, cloths, as printing medium to be employed in the ink-jet textile printing system, extend in wide variety, such as natural fibers, e.g. cotton, silk, wool and so forth, synthetic fibers, e.g. nylon, rayon, polyester and so forth, and mixed fabric of these fibers. Accordingly, in order to satisfactorily perform printing for the cloths consisted of such wide variety of fibers, it is desirable to adapt dye of the ink to a material of respective fibers. For example, reactive dye is preferred for cotton and silk, acid dye is preferred for nylon, disperse dye is preferred for polyester fiber, metal complex salt dye is preferred for wool, and vat dye or pigment is preferred for cotton. Amongst, disperse dye, metal complex dye, vat dye and pigment are known as a coloring agent insoluble in water or a coloring agent having low solubility in water.
Associating with necessity of use of inks depending upon kinds of the printing medium, following several problems occur.
First of all, in order to prepare water based ink employing water insoluble dye or dye having low solubility, it is typically performed to prepare fine particle of material of dye and to disperse the fine particle dye material into water by dispersing agent for emulsification. However, when the water based ink in which the dispersing agent is dispersed and emulsified, coagulation and sedimentation of the dye in the ink can be caused as the time going to cause variation of dye density resulting in fluctuation of printing density, or, in turn to cause plugging of an ink passage.
With respect to such problem, there has been proposed in Japanese Patent Application Laid-open No. 57342/1986 to provide a function for stirring the ink to prevent the coagulation or the sedimentation of the dye in the ink by constantly operating such stirring function.
However, only by the construction of the prior art proposed in the above-identified publication, it can be insufficient for satisfactorily using the water based ink employing the water insoluble or the dye having low solubility.
For example, in the case that a motor for performing stirring is driven constantly during use of the ink-jet textile printing apparatus, it is inherent that a bubble is generated in the ink and dissolved oxygen is absorbed into the ink. Even when stirring force is made smaller, it is still difficult to completely avoid generation of the bubble. In such case, according to elevating of an ink temperature, the bubble and the dissolved oxygen may be grown to form a greater bubble. Such large bubble may be a cause of faulty ejection, such as ink ejection failure and so forth. The problem of the faulty ejection caused by the grown bubble is particularly remarkable in the case where a head of the system for ejecting the ink by generating bubble utilizes thermal energy.
On the other hand, in the case that a period of stirring is excessively long, it is experimentally confirmed that dispersing ability of the dye can be lowered to cause fluctuation of the printing density. A reason for causing the fluctuation is estimated as follows. By stirring, a possibility of collision between dye molecules can be increased to accelerate coagulation, and the sedimentation of the dye can be promoted to cause non-uniformity of the ink density. Also, by acceleration of the coagulation, an average grain size of the dye becomes greater to cause plugging in a filter in the ink passage or plugging in the ejection openings.
Furthermore, a construction of the prior art is not practical even in the viewpoint of a life of a stirring motor. More specifically, in the case of a textile printing apparatus, different from an ordinary printer used in an office, it is typical to be operated continuously over whole days, i.e. 24 hours, and requires durability of the apparatus over 5 years or more, as industrial facility. Accordingly, a required lift for the stirring motor should be quite long in operation period. It is quite difficult to find out the motor satisfying such requirement. On the other hand, as one solution for solving such problem, the motor may be replaceable. However, this is not desirable in view of construction of the overall apparatus and in the viewpoint of cost.
Secondly, among various dyes, properties are differentiated such that the reactive dye and acid dye are water soluble, whereas dispersing dye, metal complex salt dye, vat dye and pigment are water insoluble or have low solubility. Accordingly, physical property, characteristics and so forth of the inks are differentiated.
However, in the conventional ink-jet textile printing apparatus, when the inks having different properties are used, dedicated apparatus adapted for respective inks are employed and set to a use condition adapted to respectively corresponding inks. Therefore, cost for printing is increased. Also, a large space is required for installing a plurality of textile printing apparatuses.
It is an object of the present invention to provide an ink-jet printing apparatus which can satisfactorily perform printing with employing an ink containing water insoluble dye or dye having low solubility without causing a problem of bubbling caused by stirring of the ink even when the apparatus is continuously operated for a long period.
Another object of the present invention is to provide an ink jet printing apparatus which makes stirring operation of stirring means variable to make it possible to intermittently perform stirring operation for a predetermined period during printing operation of the printing apparatus, for example.
A further object of the invention is to provide an ink-jet printing apparatus which permits use of a plurality of kinds of inks in a single apparatus and thus is suitable for textile printing.
A still further object of the invention is to provide an ink-jet printing apparatus which can identify kind of inks, select one of predetermined printing modes depending upon the identified kind of ink and perform printing in the selected printing mode.
In a first aspect of the present invention, there is provided an ink-jet printing apparatus for performing printing by ejecting an ink to a printing medium by using an ink-jet head, comprising:
executing means for executing operation associated with printing and specific to a kind of ink to be employed in printing.
In a second aspect of the present invention, there is provided an ink-jet printing apparatus for performing printing by ejecting an ink to a printing medium by using an ink-jet head comprising:
ink supply means for supplying the ink to the ink-jet head;
stirring means provided in a part of the ink supply means for stirring the ink to be supplied; and
stirring control means for making stirring operation of the stirring means variable.
In a third aspect of the present invention, there is provided an ink-jet printing apparatus for performing printing by ejecting an ink to a printing medium by using an ink-jet head, comprising:
judging means for making judgement of kind of the ink to be ejected from the ink-jet head;
setting means for preliminarily setting printing mode per kind of ink; and
control means for selecting one printing mode among printing modes preliminarily set by the setting means depending upon kinds of ink judged by the judging means and for performing printing of the printing mode selected.


A rotatable accessory includes a table top and a flipping mechanism. The flipping mechanism includes a first connecting portion and a second connecting portion. A compression spring is arranged between one side of the first connecting portion and the second connecting portion. The first connecting portion and the second connecting portion are each provided with a first blind hole facing the compression spring. Both ends of the compression spring respectively extend into the two first blind holes and abut on the bottom surface of the first blind hole. The other side of the first connecting portion and the other second connecting portion are connected by a guide hole and a guide column. The rotatable accessory can be mounted on a chair or a bed to allow users to place portable small objects such as mobile phones and cups on the rotatable accessory.

A chair is a type of seat with a backrest (and an armrest), and a bed is a type of bedding. At present, users have nowhere to place objects such as mobile phones, cups or keys when using the chair or bed without a table, which causes the users much inconvenience. In the prior art, some chairs or beds are provided with table tops for use, however, most of these table tops cannot be folded and stored.
Therefore, it is imperative to improve the technical solutions in the prior art.

Rotatable accessory and folding chair using the same


The present disclosure provides a texture detection module, a method for driving the same and a display device. The texture detection module includes: an emission electrode layer; a receiver electrode layer; and a piezoelectric film between the emission electrode layer and the receiver electrode layer. The emission electrode layer includes emission electrodes, first emission signal lines and second emission signal lines. The emission electrodes include first emission sub-electrodes and second emission sub-electrodes that are insulated from the first emission sub-electrodes. The first emission sub-electrodes are arranged in N rows and M columns, N and M are both positive integers; the first emission sub-electrodes located in an identical row are electrically coupled to one identical first emission signal line. The second emission sub-electrodes are arranged in X rows and Y columns, X and Y are both positive integers; the second emission sub-electrodes located in an identical column are electrically coupled to one identical second emission signal line.

At present, in the ultrasonic fingerprint identification technology, when reflected waves touch textures (fingerprint or palm print), due to differences between valley positions and ridge positions of the textures, vibration intensities of the reflected waves of different textures will be different. Therefore, by detecting the vibration intensities of the reflected waves, valley positions and ridge positions of a finger can be determined, thereby realizing texture identification.
However, regardless of whether the reflected waves are detected by peak detection or amplitude modulation in the related art, there is a problem of low accuracy of texture identification.

Texture detection module, method for driving the same and display device


A resinous film at least partially formulated from a recycled resin and containing a vapor phase corrosion inhibitor. One embodiment of the invention is a single layer film which is formulated from three components. The first component is a recycled resin such as polyethylene, the second component is a fresh resin identical to the first, and the third component is a vapor phase anti-corrosion agent. Multi-layer films are also included. The films emit the anti-corrosion agent over a period of time to thereby protect items encased by the film.

This invention relates in general to plastic film products, and in particular to a plastic film containing an anti-corrosion agent and wherein at least a portion of the film is formulated with recycled plastic.
Recycled resins represent an important and significant source for material useable in the production of plastic products. ASTM standard D 5033-90 defines the various types of recycled plastics. Non-limiting examples of such plastics are post consumer recycled plastics which are defined in the ASTM standard as "products generated by a business or consumer that have served their intended end uses, and that have been separated or diverted from solid waste for the purpose of collection, recycling, and disposition." After use, discarded recyclable items are processed to yield a resin usually supplied in pellet form which can be used again in the formulation of another product. Such reuse is beneficial to the environment and acts to conserve natural resources.
Because the history of recycled resin is unknown, however, it can be possible that this resin will have corrosive properties which can cause an untoward effect upon, for example, an article which is susceptible to corrosion and which is subsequently packaged within a film containing a recycled component. Commonly assigned U.S. Pat. No. 5,139,700, incorporated herein, discloses films having incorporated therein corrosion inhibitors for the protection of items to be packaged by those films. However, because the resins used for the described films are fresh, no need existed to address a problem of corrosion causation by the resin itself. A need is thus evident for incorporating anti-corrosion agents with recycled resins to thereby counteract possible corrosive agents therein while promoting effective utilization of a recycled commodity.
It is therefore a primary object of the present invention to provide a resin film containing a vapor phase anti-corrosion agent and wherein at least one component thereof is a recycled plastic.
Another object of the present invention is to provide a resin film formulated at least in part from a recycled plastic and containing an effective amount of a vapor phase anti-corrosion agent sufficient to overcome corrosive agents within the recycled plastic and to provide corrosion protection for items subsequently encased by the film.
Yet another object of the present invention is to provide a multi-layer laminate film wherein at least one of the layers is formulated at least in part from recycled plastic and wherein the film possesses vapor phase anti-corrosion properties.
These and other objects of the present invention will become apparent throughout the description which now follows.

Anti-corrosion plastic film containing recycled resin


The invention relates to a method for the preparation of stable suspensions of metal oxide nanoparticles, in which uncharged metal oxide nanoparticles are first treated with a non-ionic surfactant in a polar organic solvent under certain conditions, and the suspension obtained is then treated with a charging solution. The suspensions of the invention can be used for preparation of high quality metal oxide films by electrophoresis deposition (EPD).

Stable suspensions of metal oxide nanoparticles are important for a variety of applications and processes. Basically, the formation of stable suspensions can be achieved by two methods (alone or together): electrical charging of the surface to cause coulombic repulsion between the particles and steric effects that are usually achieved by the adsorption of organic materials on the nanoparticles surface. Depending on the material and application, one should choose the preferred method with the understanding that the adsorption of materials on the particles surface induces impurities to the system. For some applications such as optic, electronic, optoelectronic, solar energy conversion and others, it is important to process at low temperatures (around 500° C. for inorganic devices and less than 150° C. for plastic based systems) and minimize the contamination of final products with non-volatile impurities.
One of the possible applications of stable suspensions of charged metal oxide particles is electrophoretic deposition (EPD). EPD is a useful way for the preparation of thick binder-free particulate films on conductive substrates. In the EPD method, the charged particles in suspension are moved to the substrate by the applied voltage, and then are deposited on the substrate. In this case, particle charging provides two effects: coulombic repulsion for the formation of a stable suspension and charging that allows particles movement to the opposite charged electrode. No deposition of the particles by EPD occurs if they are not charged.
A wide variety of additives can be used to charge particles and thus produce well-dispersed suspensions (Sarkar and Nicholson, 1996; Zhitomirsky, 2002; Koura et al., 1995; Zhitomirsky, 1998; Special Issue on "Electrophoretic Deposition: Fundamentals and Applications", 2004). Most of the dispersing and charging additives are oligomeric or polymeric ionic or polar organic compounds, such as polyethylenimine, phosphate ester, poly(dimethyl-diallylammonium chloride), trioxadecanoic acid and acrylate-acrylamide copolymers. These dispersing and charging additives are usually applied for a dense ceramics producing, and removed during sintering at high temperatures (1200-1700° C.).
A general system composed of iodine, acetone and water as additives for metal oxide particles charging in suspensions with polar organic liquid is also known (Zhitomirsky, 2002; Koura et al., 1995; Zhitomirsky, 1998). The advantage of this composition derives from the ability to remove all of its components from produced metal oxide films at quite low temperature.

Method for preparation of stable metal oxide nanoparticles suspensions


A flat plate audio transducer. A front panel and a back panel are connected via a frame. One or more electromagnetic actuators are mounted between the two panels. Voice coils are used as the actuators in some embodiments. Stiffening braces are preferably run between groups of actuators to prevent unwanted resonance phenomena. In some embodiments an actuator array moves both the front and back panels. In other embodiments only one panel is moved. The flat plate transducer is configured to mount on a room wall in a position that is conventionally used for decorative items such as artwork.

1. Field of the Invention.
This invention relates to the field of sound transducers. More specifically, the invention comprises a flat plate transducer that provides improved low-frequency sound and a more uniform sound distribution.
2. Description of the Related Art.
Sound transducers generally seek to efficiently and accurately transform an electrical input signal into sound waves. Electromagnetic voice coils have long been used for this purpose. A voice coil typically drives a cone suspended in a chassis. Various cabinets and waveguides are added to improve the result.
Another example is the placement of an electromagnetic driver in the throat of an elongated horn. Horn designs can be quite efficient in converting electrical energy to sound energy (5-50%). They provide effective impedance matching between the relatively dense speaker diaphragm material and the much less dense surrounding air. For this reason, they are often used in public address systems where high sound levels must be produced over a substantial distance.
A well-known approach to improving the low frequency response of a conventional electromagnetic transducer is to mount the transducer within a surrounding cabinet. FIG. 1 shows a representative example. Speaker assembly 20 includes transducer assembly 21 mounted to enclosure 32. The transducer assembly in this example is a flexible cone 26 driven by a coil assembly 24. Chassis 30 provides a physical mount for the cone and coil assembly. Chassis 30 includes a circular flange that is bolted to the perimeter of a circular opening in enclosure 32. Power is provided to the coil assembly via electrical terminals 28.
Entrapped volume 34 is a volume of air captured within the enclosure. This captured air acts as a spring to flatten the transducer assembly's overall frequency response and compensate for the attenuation in its low frequency output resulting from the mismatched acoustic impedance of the cone to the air. Bass port 36 may be provided for low frequency output.
Another approached was developed by Edward M. Long in the later 1970's. Long's approach was to electrically boost the input signal in the lower portion of the frequency band in order to drive the speaker with a greater amplitude for frequencies below the speaker's resonant frequency. The boosting was accomplished by electrical circuitry contained within an external amplifier or in some instances within the speaker assembly itself. Long's approach is explained in detail in U.S. Pat. No. 4,481,662.
Jose Bertagni addressed the frequency response problem by developing a flat panel transducer using a large and flexible panel set into an open frame which acts as a dipole. The Bertagni design is described in detail in U.S. Pat. No. 4,997,058. FIG. 2 depicts a physical embodiment of the Bertagni design. The figure shows a pair of Bertagni speakers. The speaker on the left is shown from the rear while the speaker on the right is shown from the front. Frame 40 mounts the transducer hardware. Base 42 provides a stable support platform.
Sound waves are produced by vibrating flat extruded polystyrene foam panels. Low frequency panel 52 is intended to produce low frequency sound while high frequency panel 54 is intended to produce high frequency sound. A separate "tweeter" (not shown) was sometimes included as part of each speaker. Low frequency coil 44 is connected to the frame via mounting bracket 50. High frequency coil 46 is likewise connected to the frame by mounting bracket 48.
Channel 54 extends through part of the thickness of low frequency panel 52. The channel is given a particular shape to tune the resonant characteristics of the flat plastic panel. Tuning weights and secondary channels are added in some versions. The net result of the Bertagni approach is a flatter frequency response.
During the 1990's a company called NXT developed a distribution mode sound radiating panel. This approach is described in U.S. Pat. No. 6,031,926 to Azima et. al. A simplified depiction of an embodiment of this invention is found in FIG. 3 (distribution mode panel 66). A flat panel 58 is connected to a relatively rigid frame 40 via an elastic connecting surround 56. Transducer 60 (typically a piezoelectric transducer) is attached to panel 58. The transducer is fed by amplifier 64. Second transducer 62 may be included as well. Panel 58 is typically a lamination of three layers. In one example the core layer is plastic foam. The outer layers on the front and back are metal foil.
With most all prior art designs, radiation resistance (impedance), efficiency, and the interaction between a speaker and the room surrounding it (room resonance modes) are neglected. Instead, the prior art designs attempt to optimize a flat frequency response in the area near the speaker (the "near field"). The enclosure and loudspeaker are an acoustic point source. At frequencies greater than the dimensions of the loudspeaker cone, the radiated energy becomes spherical and the listener's experience is then highly dependent on the listener's position within the room.
Prevailing design parameters for low frequency speakers were set out in a 1970 Audio Engineering Society paper by Thiele and Small. These parameters are known as "Thiele-Small parameters" within the art. High fidelity low frequency loudspeakers have been designed using these parameters since that time. However, using the Thiele-Small parameters results in a loudspeaker with very low efficiency (usually a few percent or less). Using these parameters also ignore the interaction between a loudspeaker and the room surrounding it.
A loudspeaker transducer creates extremely small changes in air pressure (sound pressure). The electrical current used to drive such a transducer faces an internal source impedance and drives an external load impedance (the surrounding air). The impedance of the air is low because of its low density. The internal source impedance is high. Hence, there is a considerable mismatch between the source impedance and the load impedance. The result is that most of the electrical energy put into a direct radiating loudspeaker will be converted to heat and will not be converted to sound energy. The problem is worse at low frequencies, where the physical size of the source (the cone diameter) will be small compared to the wavelength of the sound wave produced. The result is that air slips around the speaker diaphragm instead of changing pressure. Efficiencies of just a few percent are the accepted norm.
At higher frequencies the wavelength of the sound wave produced is of course smaller compared to the loudspeaker cone dimensions. The sound in this frequency range becomes directional and the driver becomes more efficient. If a driver can be made to radiate directional waves across its entire frequency operating range, efficiency is increased.
Thiele-Small design parameters suggest the use of a large enclosure and a relatively small moving diaphragm (cone) to make up for the loss in low-frequency efficiency from a small transducer. These systems increase amplitude using the resonance of the air volume trapped behind the cone combined with the mass and stiffness of the cone suspension. These parameters set a low frequency cutoff, below which the velocity of the cone drops significantly.
Thiele-Small parameters dictate a cabinet enclosure area to cone surface area ratio of about 10 to 1 or higher. A rigid enclosure is needed to prevent cabinet resonance modes. The use of these parameters trade efficiency for bandwidth and define an acoustic point source at low frequencies. Efficiency is given up in exchange for extended low frequency response. The user of the parameters dominates the commercial market.
The solution proposed in the present invention incorporates a very large diaphragm relative to the enclosure surface area and very small-displacement actuators as compared to traditionally-designed loudspeakers. Efficiency is increased via improved impedance matching, room acoustic frequency response is improved by radiating low frequencies from a very large area diaphragm.


A cellular telephone assembly includes a front shell having a mounting pin and a locating pin, and having a plurality of keyholes, a base shell having a mounting pin and a locating pin, and a light guide formed of substantially translucent material and having a substantially planar shape, the light guide having a mounting boss with a hole therethrough, the centering pins of the front shell and base shell being insertable in the hole from opposite side thereof and frictionally engageable therein, the light guide further having a locating hole, the locating pins of the front shell and base shell being insertable in the locating hole. The mounting pins and locating pins of the front and base shells cooperate with the mounting boss and locating hole of the light guide for ready alignment and fastening of the components. The invention includes a method for assembling the components, which allows the formation of convenient sub-assemblies of the components before final assembly.

Cellular telephones typically include several parts that must be assembled within front and base shells or covers. These parts include the display, the keypad, a light guide for distributing light to the display and keypad, and a printed circuit board that contains the telephone's electronics. In addition, a telephone generally includes other components such as a microphone and speaker.
Assembly of such a telephone can be difficult because of the small size and delicate nature of the parts, and because of the relative position and orientation in which the parts must be assembled.
The present invention provides a method of assembling a cellular telephone that facilitates the assembly process. The method of assembly of the invention permits the formation of subassemblies of the parts, which may then be more easily handled for further assembly or processing prior to final assembly.
The present invention also provides a cellular telephone having a light guide that facilitates the alignment and fastening of the front and base shell of the telephone. The light guide according to the invention includes a mounting hole positioned in a central region of the light guide and a locating hole positioned remote from the mounting hole. Pins in the front and base shells are aligned with the mounting hole and locating hole to facilitate assembly of the shells.
Alternatively, a mounting pin and locating pin may be provided in only one of the front shell and the base shell, the pins having sufficient length to extend through the components that form a subassembly, as further described below.
The mounting boss and locating hole in the light guide, and, correspondingly, the mounting pins and location pins in the front shell and rear shell are located to facilitate the alignment f unction. Preferably, the mounting boss and mounting pins are formed a central portion of the light guide and shells, respectively, and the locating hole and locating pins are formed near an edge of the light guide and shells.
According to another aspect of the invention, the pins in the front and rear shells that mate with the mounting hole of the light guide are shaped for securable engagement with the mounting hole for fastening of the light guide and front and rear shells. The pins and the mounting hole may be shaped for a force fit, for frictional engagement, or with a detent and mating groove, for example.
According to the method of the invention, a front shell subassembly may be formed by placing a keypad having a plurality of keys in a front shell with the keys extending through keyhole in the front shell, positioning the light guide in the front shell, fastening the light guide to the front shell by frictionally engaging a mounting pin on the front shell with a mounting hole in the light guide, and inserting a locating pin on the front shell in a locating hole in the light guide.
According to another aspect of the method, the base shell may be fastened to the front shell subassembly by the steps of aligning the base shell with the front shell by positioning a base shell mounting pin with the mounting hole in the light guide, and positioning a locating pin in the base shell with the locating hole in the light guide, and fastening the base shell to the front shell by frictionally engaging the base shell mounting pin in the mounting hole in the light guide.
The method in accordance with the invention further includes the step, before fastening the base shell to the front shell, of positioning a printed circuit board in the base shell by aligning holes in the printed circuit board with the mounting pin and locating pin of the base shell so that the pins extend through the holes in the printed circuit board.
According to another aspect of the invention, the light guide has a shape that improves the distribution of light to a display and keyboard, illuminating the display and keyboard in a more uniform manner that substantially eliminates dark and bright areas. The light guide of the invention more provides a light source coupling to receive and transmit light more efficiently into the light guide, thus, more effectively distribute light throughout the light guide. Accordingly, a light guide of the invention provides a brighter display and keys, and may require fewer light sources than conventional light guides. The light guide may thus saves manufacturing expense and time, component cost, and reduces battery energy consumption in the completed device.
According to the invention, the light guide comprises an element formed of a translucent material having an upper surface, a lower surface and a peripheral edge. The element is preferably a planar, rectangular component shaped to correspond to the keyboard and display of a telephone.
According to the invention, a plurality of light coupling recesses is provided on the peripheral edge to transmit light into the light guide. The light coupling recesses are preferably arcuately shaped, and more preferably semicircular. This feature helps to guide light from light sources uniformly into the light guide, thus avoiding bright and dark regions. In a preferred embodiment of the invention, the light coupling recesses are positioned on one side of the light guide in equally spaced relationship. In this way, a maximum amount of useful light is transmitted to illuminate a desired portion of the light guide, for example, that portion serving as a display screen backing. Alternatively, the light coupling recesses may be positioned as convenient around the periphery of the light guide for a desired illumination pattern.
According to another aspect of the invention, a plurality of reflecting recesses are provided on the peripheral edge of the light guide to reflect light striking the edge toward the key holes. According to a preferred embodiment of the invention, the reflecting recesses are positioned between adjacent keys hole locations. The reflecting recesses may be arcuately shaped or formed with two or more facets. According to a preferred embodiment, the reflecting recesses are V-shaped.
According to yet another aspect of the invention, the upper and lower surfaces of the element may be formed as glossy reflective surfaces, which facilitates the transmission of light through the light guide while minimizing the leakage of light from the surfaces.

Cellular telephone assembly and method for assembling a cellular telephone


A polygon mirror drive motor according to the present invention comprises a stator and a rotor having a hexahedron-shaped polygon mirror and a rotation drive shaft. The polygon mirror in one preferred mode is comprised of two square faces that are parallel with each other and orthogonal to said rotation drive shaft, the two square faces having each a center hole in which said rotation drive shaft is inserted, and four mirror facets that are parallel with said rotation drive shaft. In the polygon mirror, a value of D/L is preferably in a range of from 0.37 to 0.41 where D is a diameter of said center hole and L is an edge length of said two square faces.

1. Field of the Invention
The present invention relates to a polygon mirror drive motor for use in a laser beam printer, a photocopier or the like, and is equipped with a polygon mirror for deflecting and scanning a laser beam.
2. Description of the Related Art
In a laser beam printer or a photocopier is utilized a polygon mirror drive motor. In the polygon mirror drive motor, a polygon mirror configured by combining a plurality of mirror facets into a polygonal shape, seen in plain view, is mounted in a rotor portion that rotates with respect to a stator. With this, the polygon mirror can rotate at high speed to deflect and scan a laser beam being incident upon the plurality of the mirror facets. A scanning light beam produced by deflecting and scanning the laser beam with the polygon mirror creates an image on a photoreceptor or paper.
By the way, since a polygon mirror that is produced with a plurality of mirror facets formed into a shape of a polygon is deformed by a centrifugal force when the polygon mirror rotates at high speed, there exits a light scanning optical device that is capable of correcting the deformation (Refer to Japanese Patent Application Publication H09-43529).
In addition, there is a polygon mirror that realizes a high degree of optical precision in a motor mounting hole, a motor mounting base and the like, while reducing its weight and costs by arranging four mirror facets in square in plain view.
FIG. 1 illustrates a top view of an example of a polygon mirror used in a light scanning optical apparatus of related art. FIGS. 2A and 2B illustrate a top and a cross-sectional view of another example of a polygon mirror of related art, respectively.
The example of a polygon mirror 100 used in the related art light scanning optical apparatus illustrated in FIG. 1 is disclosed in Japanese Patent Application Laid-open Publication H09-43529. The polygon mirror 100 has a deflective reflection surface 101a that has been shaped into a slight concave when the polygon mirror 100 stays stationary, as shown in a dashed line in FIG. 1. When the polygon mirror 100 rotates at high speed around a rotation axis 101b, the deflective reflection surface 101a deforms so as to bulge out to take a shape of a deflective reflection surface 101a′ that is shown in a full-line in FIG. 1 due to a centrifugal force caused by high-speed rotation. Therefore, while a focal point of the polygon mirror 100 lies in front of a surface to be scanned when the mirror 100 stays stationary, the focal point falls upon the surface to be scanned when the mirror 100 rotates at high speed, thereby compensating a positional change of the focal point stemming from the deformation caused by the rotation of the polygon mirror 100.
Another example of a rotation polygon mirror is disclosed in Japanese Patent Application Laid-open Publication H09-61743 as shown in FIGS. 2A and 2B. The rotation polygon mirror 200 is shaped into a hexahedron having six square faces of 4 mm thick. The rotation polygon mirror 200 has a center core 201 in the center thereof and an optical face core 202 that surrounds the center core 201. Through the center core 201 is pierced a hole 201a for a motor shaft and formed of polycarbonate containing glass fiber having a rigidity. The optical face core 202 is formed of polycarbonate as thermoplastic material having optical properties suitable for a rotational polygon mirror. With the above configuration, the above publication recites that the mirror 200 can be produced with high positional accuracy in a motor shaft hole, a base level or the like and thereby with high optical accuracy while keeping production costs for the mirror 200 reduced.
In case of the polygon mirror 100 of an example used for the conventional optical scanning optical apparatus shown in FIG. 1, it is necessary to design the deflective reflection surface 101a so that the surface 100a takes a shape of an appropriate concave, taking account of an amount of the deformation caused when the deflective reflection surface 101a is forced to bulge out by the centrifugal force at the time of high-speed rotation. However, it is difficult to estimate in advance an amount of the deformation of the deflective reflection surface 101a, and also difficult to create the deflective reflection surface 101a into a concave in accordance with the estimation. On top of that, considering a technology trend in that a further increase in the rotation speed of the polygon mirror 100 has been expected in view of a recent progress in a laser beam printer or a photocopier in terms of highly definitive and precise imaging, a deformation of deflective reflection surface 101a caused by a centrifugal force has now drawn a great deal of attention, since the centrifugal force at the time of high-speed rotation of the polygon mirror 100 is proportional to the number of rotations to the 2nd power. For this reason, it is still more difficult to estimate the amount of the deformation of the deflective reflection surface 101a.
Moreover, an upper surface, a lower surface, and four mirror facets are easily obtained with high dimensional precision, the four mirror facets being configured to surround the upper and the lower surface and to become a side face of the polygon mirror, since the polygon mirror 200 shown in FIGS. 2A and 2B is formed into a hexahedron. However, since the outside of a main core 201 having a high rigidity is covered with an optical surface core 202 having a favorable optical property, a production of the rotation multifaceted mirror (polygon mirror) 200 needs an increased number of processes, thereby resulting in high production costs.
In view of the above, it has been desired that a polygon mirror drive motor which can control the deformation of each mirror facet caused by the centrifugal force of high-speed rotation is obtained while producing easily a polygon mirror having sufficient dimensional precision by connecting a total of four mirror facets into a square in plain view.


Disclosed is a digital control servo system for read/write head positioning in data recording disk files of the type which use voice coil motor (VCM) actuators for positioning the head, with improved modelling of the servo system in saturated seek mode. The VCM has a characteristic torque factor which varies in accordance with a predetermined relationship to head position and with age and temperature, and the servo system drives the VCM in a saturated seek mode at a maximum level of current which has a low frequency variation due primarily to temperature change. The servo system computes an estimated VCM control representing the VCM current, computes estimates of the state of the VCM including head position and velocity, and computes from an algorithmic model, predictions of head position and velocity. The improved modelling changes the algorithmic model to reflect the actual torque factor of the VCM and actual maximum level of current in saturated seek mode rather than nominal torque factor and VCM current. The preferred method is to employ scaling factors representing the ratio of measured torque factor to nominal torque factor, and representing the ratio of measured maximum level of current to nominal, to scale the model, and then to compute predictions of the state of the VCM in saturated seek mode from the scaled model and the current values of the states.

Disk files are information storage devices which utilize a rotatable disk with concentric data tracks containing the information, a head for reading or writing data onto the various tracks, and an actuator connected by a support arm assembly to the head for moving the head to the desired track and maintaining it over the track centerline during read or write operations. The movement of the head to a desired track is referred to as track accessing or "seeking", while the maintaining of the head over the center line of the desired track during a read or write operation is referred to as "track following".
The actuator is typically a "voice coil motor" (VCM) which comprises a coil movable through the magnetic field of a permanent magnetic stator. The application of current to the VCM causes the coil, and thus the attached head, to move radially. In the absence of bias forces, the acceleration of the coil is proportional to the applied current. This current is applied by a power amplifier in response to a control input. If the input control is small enough, then the applied current is proportional to the control input and the power amplifier is nonsaturated; if the control input is too large, the applied current reaches a maximum possible value, and the power amplifier is saturated.
In disk files which have a relatively high density of data tracks on the disk, it is necessary to incorporate a servo control system to efficiently move the head between tracks and to maintain the head precisely over the centerline of the desired track during read or write operations. This is accomplished by utilizing prerecorded servo information either on a dedicated servo disk or on sectors angularly spaced and interspersed among the data on a data disk. The servo information sensed by the read/write head (or the dedicated servo head if a dedicated servo disk is used) is demodulated to generate a position error signal (PES) which is an indication of the position error of the head away from the nearest track centerline and to detect the track number or position sample.
In a disk file digital servo control system, a microprocessor utilizes a control signal algorithm to calculate a digital control signal based upon the digital values of certain state variables such as head position, VCM current and head velocity. The digital control signal is converted to an analog signal and amplified to provide input current to the VCM. Such a digital servo control system is described in assignee's U.S. Pat. No. 4,679,103 incorporated by reference herein, and is a system which, as part of the computation of the control signal to the actuator, makes use of the state estimator algorithm to estimate the state (i.e., position, velocity and acceleration or current input to the VCM) of the head. In this type of system, a microprocessor receives, at discrete sample times, digital values corresponding to the PES, position sample, and the VCM input current, and computes, through the use of the state estimator algorithm, a digital control signal. The digital control signal is then converted to an analog signal to provide a power amplifier control signal. A power amplifier then generates a new VCM input current. The method of estimating the state of the physical plant to be controlled in such a digital servo control system requires the use of estimator constants, the derivation of which is described in Digital Control of Dynamic Systems, Franklin and Powell, Addison-Wesley Publishing Co. (1983), chapter 6, pages 131-139. In the case of a disk file, these estimator constants are dependent upon the values of certain physical parameters of the disk file, such as the moving inertia of the coil and head/arm assembly, the VCM force, or torque, factor (the torque applied to the coil per unit of input current), the gain of the VCM power amplifier, the PES gain and the time between PES samples (the PES sampling time).
The VCM current is fed back directly to the input to the power amplifier where it is summed with the analog control signal. This effectively changes the integrating power amplifier into a low pass filtering power amplifier, with linear input output characteristics. Thus, when the power amplifier is not saturated, the VCM current and state of the head can be easily modeled, based upon the linear characteristics of the servo system. During long seeks, when the power amplifier is saturated, the linear model is not accurate. During this phase of operation of the disk file, the servo system operates in open loop and the state estimator algorithm is modeled based upon the known VCM characteristics during saturation. The saturation model of VCM current incorporates the effects of both the back electromotive force (back EMF) and the coil current rise time.
The microprocessor in the digital servo control system determines which VCM current model to use by a determination of when the power amplifier is in saturation. In the example described in assignee's U.S. Pat. No. 4,914,644, the microprocessor determines power amplifier saturation based upon a value of the velocity error, which is the difference between the commanded velocity and the estimated velocity. When the velocity error is larger than a predetermined threshold, then the power amplifier is thought to be saturated and the saturation model is used.
The prior art patents discuss changes to the linear nonsaturated model resulting in modifications to the control signal so as to make the VCM more precise or to more quickly position the head correctly. In assignees' U.S. Pat. No. 4,835,633, which is incorporated herein by reference, the actual current input to the VCM is fed back to the nominal prediction model and, in the '644 patent, the actual current is estimated using a nominal current model and fed back to the nominal prediction model to estimate the next position of the head. The torque factor, as shown by the '633 patent, varies over the length of the stroke by up to 17% and can vary from device to device and over time in the same device, accounting for some modelling error. In addition, the assignee has found that the torque factor may vary by an additional 4% with temperature.
The '633 patent takes temperature change into account with respect to the torque factor as part of a measurement of the current state of the linear acceleration factor, but does not consider the change in the saturated seek mode, as the mode operates only at maximum current which is not subject to changes in the control.
Japanese published patent application 5-266615 measures the temperature directly in the magnetic circuit and measures the driver current flow directly, deducing the corresponding temperature. From a stored lookup table, the decrease in the torque constant is found and is used to adjust the gain of the linear servo loop, so that overall stability is improved.
The prior art patents, however, use only a nominal saturated model because the system is operating in open loop with the control signal at the level required to maintain the maximum current to the VCM actuator. The major problem described, for example, in assignee's U.S. Pat. No. 4,697,127, at col. 9, 11. 51-56 is that the coil resistance (and therefore, the maximum servo current) in saturated seek mode, indeed, even during nonsaturated seek, varies up to 30% with temperature. Therefore, the nominal model is built with sufficient safety to account for the worst case of this parameter.
Assignee's U.S. Pat. No. 5,119,250 attempts to overcome the difficulty of using the worst case model by modifying the point at which the current is switched from acceleration current to deceleration current, but still within a velocity profile which assumes the worst case conditions.
Whether or not the worst case model is used, an important problem in using the nominal model to predict the position and velocity of the VCM, is that the error between the predicted position and actual position at each servo sample time may become large. Typically, this error is integrated during the seek to provide a corrective "dynamic windage" term that is added to the control. If the error is large, this term will increase in size ("windage windup"), and the resulting control may be too large to "unwind" in time, resulting in overshoot of the target. Additionally, the windage estimate is typically used to provide the initial linear model static windage estimate such that the error will degrade the settle characteristics and likely the settle time of the seek.

Digital servo control system for a data recording disk file with improved saturation modelling

International Business Machines Corporation


An optical pickup includes: a lens holder having an objective lens, an optical component, a radiator plate formed of a sheet metal, and a base member on which the lens holder and the optical component are mounted, the base member being formed of a synthetic resin molded body. The base member has a base plate portion in which a light passage hole is opened in such a manner as to face the objective lens, a mounting wall on which the optical component is mounted and a mounting piece of the radiator plate is secured, and an enclosure wall that is erected substantially on an opposite side to the mounting wall across the light passage hole. The surface plate portion extends toward the enclosure wall and an end of the surface plate portion is fixed to a top portion of the enclosure wall.

1. Field of the Invention
The present invention relates to an optical pickup and more particularly to an optical pickup which is devised to allow the resonance frequency band of a base member on which a light emitting element and a collimator lens are installed to deviate from a vibration frequency band generated in association with the operation of a lens holder having an objective lens.
2. Description of the Related Art
FIG. 8 shows a plan view of an example of the schematic configuration of an optical disk apparatus using an optical pickup 1. In the drawing, the optical pickup 1 includes a base member 2 on which a lens holder 3 equipped with an objective lens 31 is installed and is controlled to access (or is controlled to travel to) an optical disk D along a radial direction thereof when bearings 21 and a rail bearing 22 which are provided on the base member 2 are caused to travel while being guided, respectively, by a guide shaft 52 and a guide rail 53 which are provided on a frame-shaped drive chassis 51. In addition, a rack 23 provided on the base member 2 meshes with a threaded shaft 54 mounted on the drive chassis 51, so that the rotational motion of the threaded shaft 54 is translated into the linear motion of the base member 2 by the rack 23. Furthermore, the drive chassis 54 is mounted on a frame 56 which is raised and lowered via a cam mechanism 55. The frame 56 is fixed to a stationary frame 57 such as a box body. Then, the optical disk D as a recording medium is mounted on a turntable 58 set on the frame 56 for rotation.
FIG. 9 is an explanatory drawing of an optical system of the optical pickup. As shown in the drawing, the optical system of the optical pickup includes the aforesaid objective lens 31 in addition to a light emitting element 32 made up of a light emitting diode or the like, a light receiving element 33, a half mirror 34 and a collimator lens 35, and the objective lens 31 is equipped on the lens holder 3, as has been described above, whereas the other components including the light emitting element 32 are mounted on the base member 2. Then, laser light emitted from the light emitting element 32 is guided to the collimator lens 35 by the half mirror 34 so as to become a flux of parallel light, which then transmits through the objective lens 31 so as to be emitted onto the optical disk D, and reflected light therefrom is received by the light receiving element 33 via the objective lens 31, the collimator lens 35 and the half mirror 34.
In this optical pickup, in order to correct a change in the positional relationship between the optical disk D and the objective lens 31 which would occur in association with the warp or eccentricity of the optical disk D, the lens holder 3 is controlled to be displaced in a focusing direction and a tracking direction relative to the optical disk D by the action of a driving unit 36. In general, the driving unit 36 is made up of a combination (not shown) of a supporting unit for supporting the lens holder 3 on the base member 2 in such a manner as to be displaced in the two directions, a coil and a magnet.
In the optical pickup, a proper vibration frequency used when the lens holder 3 is controlled to be displaced in the focusing direction and the tracking direction is adjusted so as to be accommodated within a certain band. Here, the vibration frequency of the lens holder 3 which has been properly adjusted is referred to as an adjusted frequency.
There is a case that the base member 2, on which the lens holder 3 which is controlled to be displaced in the focusing direction and the tracking direction is installed, resonates with the vibration of the lens holder 3 which occurs when the lens holder 3 is controlled to be displaced. Then, when the base member 2 resonates, the vibration of the base member 2 is then transmitted to the turntable 58 via the guide shaft 52 and the guide rail 53, the drive chassis 51 and the frame 56, which were described above by reference to FIG. 8, whereby since the optical disk D vibrates when the turntable 58 vibrates, the servo properties of the lens holder 3 are reduced, leading to the reduction in reliability in writing and reading by the optical pickup 1. Then, in the event that in the base member 2, the resonance frequency band overlaps the adjusted frequency of the lens holder 3 or resides in the vicinity thereof, even if the adjusted frequency has been set properly, the servo properties of the lens holder 3 are reduced, and no satisfactory value cannot be obtained for the writing and reading performance of the optical pickup 1, thereby resulting in the failure of adjustment.
The resonance of the base member 2 occurs prominently when the base member 2 is made of a thin synthetic resin molded body. FIG. 7B shows a gain curve and a phase curve in the focusing system when the base member 2 is made of a thin synthetic resin molded body, and in FIG. 7B, the resonance generated when the base member 2 resonated (vibrated) was transmitted to the turntable 58 to thereby cause the optical disk D to vibrate, and as a result, the gain curve or the phase curve was made to fluctuate irregularly in a range of 1 to 2 kHz (ranges where the irregular fluctuation occurred are indicated as G1, P1). Thus, when the gain curve or the phase curve of the base member 2 is caused to fluctuate irregularly in the range of 1 to 2 kHz, the vibration of the base member 2 is transmitted to the turntable 58 to thereby increase the vibration of the optical disk D, whereby the aforesaid adjustment is made difficult, possibly resulting in the reduction of focusing servo properties.
FIG. 10 is a schematic plan view of the base member 2 made of a synthetic resin molded body which is used in an optical pickup in the related art, and FIG. 11 is a view as seen in a direction indicated by an arrow XI in FIG. 10. On this base member 2, a light emitting element made up of a laser diode, not shown, is mounted and a radiator plate 7 made of a sheet metal is provided for radiating heat generated in the light emitting element. The radiator plate 7 includes a mounting piece 71 which is formed by bending part of the radiator plate 7 at right angles, a surface plate portion 72 and a projecting piece 73, and the mounting piece 71 is screwed to a mounting wall (not appearing in the drawing) of the base portion 2 at two locations with machine screws together with a radiator block 74 which is mounted on the light emitting element while the mounting piece 71 is being superimposed on the radiator block 74. In the conventional example, while the radiator plate 7 is screwed only to the mounting wall of the base member 2 with the machine screws, a collimator lens mounting hole (a light passage hole) 27, which is opened in a substantially central portion of a base plate portion of the base member 2, is covered with the surface plate portion.
Then, although the problem with the resonance of the base member 2 made of a synthetic resin molded body was attempted to be solved by devising the countermeasure in which the reinforcement rib is provided on the base plate portion 28 of the base member 2, since the mounting hole 27 is opened in the substantially central portion of the base plate portion, only with the reinforcement rib, a vibration mode such as bending and twisting is generated in the base member 2, and the resonance frequency band of the base member 2 which is generated when the lens holder 3 (refer to FIG. 8) is controlled to be displace has been unable to be made to deviate largely from the aforesaid adjusted frequency. Note that the gain curve or the phase curve which was explained above by reference to FIG. 7B is such as to be obtained as to the base member 2 constructed as has been described heretofore.
On the other hand, as to the optical pickup, there has been proposed a technique in which with a view to increasing the servo properties for access control by increasing the resonance frequency which deforms a fixing portion where a carriage and a holding member of a lens holder are fixed together, the rigidity of a location in the vicinity of the fixing portion is increased (refer to JP-A-9-102133). According to this technique, a cover obtained by pressing a sheet stainless steel is described as being fixed to upper surfaces of the carriage and a tracking coil. In addition, in an optical pickup device, with a view to suppressing the transmission of a reaction force of vibrations generated from a correction driving unit to a supporting body of a lens holder, there is proposed a means in which a supporting base and the supporting body are bonded together directly below a yoke functioning as the correction driving unit (refer to JP-A-2002-42356). Furthermore, it is described as a known example in which in an optical pickup device, optical system constituent components such as a semiconductor laser and a light receiving element are installed on a device frame made of a resin (refer to JP-A-2001-325740). Moreover, it is known that the optical system of an optical pickup is made up of a semiconductor laser, a collimator lens, a half mirror, a photo diode and the like (refer to JP-A-2002-352445)


A handle includes two pipes slidably engaged in two tubes which are slidably engaged in two ducts. The pipes and the ducts each includes a lower portion having an actuator and a latch. The latches may secure the pipes to the tubes and may secure the tubes to the ducts. The actuators each has a cam for disengaging the latches from the tube and the duct. The pipes and the tubes each includes a flat surface for engaging with that of the actuators and for securing the actuators in place. The pipes and the tubes and the ducts may be secured together when they are folded to the compact folding structure.

1. Field of the Invention
The present invention relates to a handle, and more particularly to a retractable luggage handle assembly.
2. Description of the Prior Art
U.S. Pat. No. 5,308,103 to Chin-Shung discloses a collapsible luggage trolley that includes a complicated structure. In addition, it is difficult to increase the number of sections or to increase the length of the handle for such a trolley.
The present invention has arisen to provide a novel structure.


Protective covers for rotors are disclosed. The protective covers may include a first liner portion contacting and covering a first portion of the rotor, and a second liner portion positioned adjacent and at least partially aligned circumferentially with the first liner portion. The second liner portion may contact and cover a second portion of the rotor. The protective covers may also include an outer casing covering the first liner portion and the second liner portion.

The disclosure relates generally to protective covers, and more particularly, to a protective cover for a rotor of a turbine system and shipping apparatuses that utilizes the protective cover when shipping and/or transporting rotors.
Due to the dimensions and intricacies of the features included in turbine rotors, it is often difficult to safely and effectively to move or transport rotors. Whether it is removing a turbine rotor from the turbine system to perform standard maintenance procedures, or shipping a new rotor to be utilized in a turbine system, rotors and their various features or components are susceptible to undesirable contact, which may result in damage to the rotor. The damage caused by undesirable contact may result in operational inefficiencies, extra required maintenance, and in some cases, replacement of components, features or the entire rotor. Damage to the rotor and its features can be costly and time consuming for operators of turbine systems.
Conventional shipping methods utilize standard packaging material and procedures to attempt to reduce damage to the rotors during transport. For example, bearings and blade areas of a rotor are typically wrapped in various layers of plastic wrap for protection. Additionally, cardboard is often placed over these areas prior to and/or in between layers of wrapping to provide additional layers of protection. However, plastic wrap and cardboard do not provide an adequate amount of protection for the rotor; especially for portions of components like the rotor bearings, which are highly sensitive to undesirable contact. Furthermore, once the rotor reaches its destination, the only way to remove this plastic wrap and cardboard is to cut it from the rotor. As a result, even if the rotor and its components are not damaged during the transportation or shipping process, the rotor may become damaged if a person cutting away the plastic wrap and cardboard cuts too deeply and undesirably contacts or cuts the rotor.

Protective cover for rotor and associated shipping apparatuses


A method of inhibiting parasitic activity is disclosed in which the biosynthesis, structure and/or function of the glycosyl phosphatidylinositol (GPI) anchor of said parasite may be affected by incorporating into said GPI anchor selected analogs of myristic acid containing various heteroatoms, substituents and unsaturated bonds, including ester-containing analogs, ketocarbonyl-containing analogs, sulfur-containing analogs, double bond- and triple bond-containing analogs, aromatic moiety-containing analogs, nitrated analogs and halogenated analogs.

This invention relates to a method of inhibiting parasitic activity by inhibiting the biosynthesis of the glycosyl phosphatidylinositol (GPI) anchor of the parasite. More particularly, the invention relates to the inhibition of parasitic activity by contacting said parasite with selected analogs of myristic acid containing various heteroatoms, substituents and unsaturated bonds.
Glycosyl phosphatidylinositols (GPIs) anchors diverse proteins to the plasma membranes of organisms ranging from the yeasts to mammals. See, e.g., the review article by Low, Biochem. J. 244, 1-13 (1987). One of the most completely characterized GPI anchors is that of the variant surface glycoprotein (VSG) of the parasitic protozoan Trypanosoma brucei. See, e.g., the research article by Ferguson et al. Science 239, 753-759 (1988), for the complete primary structure of the GPI anchors of VSG variant 117, and the review of GPI biosynthesis in T. brucei by Englund, Ann. Rev. Biochem. 62, 121-138 (1993). This parasite, in common with other African trypanosomes, evades the mammalian immune system by antigenic variation in which individual genes encoding immunologically distinct VSGs form a dense surface coat. The VSG coat acts as a macromolecular diffusion barrier which protects the parasite from lytic host-serum components.
Trypanosoma brucei is a protozoan bloodstream parasite responsible for African sleeping sickness which has a devastating effect on human health and on livestock production. Consequently, methods of inhibiting the activity of this and related protozoan parasites would have significant importance to medical science and for the development of therapeutic intervention to parasitic diseases.
Recently, in U.S. Pat. No. 5,151,445, certain myristic acid analogs have been disclosed as useful for inhibiting the growth and viability of bloodstream trypanosome parasites having a GPI membrane anchor. These analogs are oxy-substituted fatty acid analogs of C.sub.13 and C.sub.14 fatty acids or alkyl esters thereof in which a methylene group normally in carbon position from 4 to 13 of said fatty acid is replaced with oxygen. See also Doering et al., Science 252, 1851-1854 (1991).

Thienyl-containing fatty acid glycosyl phosphatidylinosital analogues used for inhibiting parasitic activity


A composition includes a polycarbonate-polysiloxane block copolymer that has at least one polycarbonate block and at least one polysiloxane block, and a surface modifying agent that includes at least one polysiloxane segment. Increased levels of the surface modifying agent can be incorporated without compromising high transmittance and low haze. The compositions also exhibit improved hemocompatibility and are therefore useful for a variety of articles that may contact blood.

Siloxane-containing polymers and copolymer have been coated on various thermoplastic articles in order to modify their surface characteristics. For example U.S. Pat. No. 6,500,549 to Deppisch et al. describes coating articles with a biocompatible film comprising polydimethylsiloxane blocks. U.S. Pat. No. 5,589,563 to Ward et al. describes coating articles with surface active endgroup-containing polymers that include a linear base polymer having covalently bonded surface active endgroups that modify the surface tension of the base polymer. U.S. Pat. No. 6,395,226 to Plunkett describes a coating for microporous hollow fiber membrane blood oxygenators that increases the resistance of the fibers to passage of blood plasma through the micropores; the coating includes an alkoxysilane/alkylsilane copolymer. This approach has the drawback of requiring separate handling and coating steps to coat the surface-modifying copolymer.
It is also known to modify the surface properties of a thermoplastic resin by blending a siloxane-containing polymer with the bulk thermoplastic resin. For example, U.S. Pat. No. 3,686,355 to Gaines et al. describes blends of a base polymer and a surface-modifying additive that may be a polycarbonate-polysiloxane block copolymer. However, the amount of surface-modifying additive required to obtain the desired surface properties often detracts from the desirable optical properties of the base copolymer.
There is therefore a need for polymer blends that exhibit desirable surface properties without requiring a surface coating step and without compromising the desirable optical properties of the base polymer.

Transparent polycarbonate-polysiloxane copolymer blend, method for the preparation thereof, and article derived therefrom


A system for locating according to a data description includes an interface and a processor. The interface is configured to receive the data description. The processor is configured to create a model-based item identification job based at least in part on the data description; provide the model-based item identification job to a set of vehicle event recorder systems, wherein the model-based item identification job uses a model to identify sensor data resembling the data description; receive the sensor data from the set of vehicle event recorder systems; and store the sensor data associated with the model-based item identification job.

Modern vehicles (e.g., airplanes, boats, trains, cars, trucks, etc.) can include a vehicle event recorder in order to better understand the timeline of an anomalous event (e.g., an accident). A vehicle event recorder mounted on a vehicle typically includes a set of sensors—for example, video recorders, audio recorders, accelerometers, gyroscopes, vehicle state sensors, global positioning system (GPS), etc., that report data, which is used to determine the occurrence of an anomalous event (e.g., a sudden stop, a hard maneuver, a collision, etc.) or a bad driver behavior (e.g., eating while driving, talking on a cell phone while driving, smoking while driving, etc.). In some situations, there is a request from emergency agencies that can be assisted using sensors of one or more vehicles—for example, an amber alert is distributed by an emergency agency (e.g., the police) to locate a target vehicle being used by a criminal. However, the sensors of the vehicles are neither aware of the alert nor able to respond to the alert and thus cannot assist the emergency agency.

Leveraging machine vision and artificial intelligence in assisting emergency agencies