A collaborative file access management system. The system can include one or more secure, collaborative files, each secure, collaborative file including a security trailer specifying at least one of an access policy and associated digital rights. The system also can include a user-layer file management application configured to limit access to the secure, collaborative file based upon the access policy. Finally, the system can include a kernel-layer file security service configured both to detect kernel-level requests to access the secure, collaborative files, and also, responsive to the detected kernel-level requests, to invoke the file management application.

1. Statement of the Technical Field
The present invention relates to the field of file security and digital rights management, and more particularly to methods and systems for transparently protecting, controlling and managing files in a collaborative environment.
2. Description of the Related Art
Prior to the advent of the information age, protecting sensitive files seemed simple—limit the number of hard copies and secure existing hard copies under lock and key. The digital revolution, however, has eased the manner in which files can be shared amongst a vast audience resulting in the inability of authors to limit the number of copies made of an electronic file and the associated distribution of those electronic files. In consequence, financial losses attributable to the misappropriation of sensitive electronic files are increasing each day.
Virtually every business supporting electronic data interchange and e-business faces the threat of cybercrime. A breach in security of an Internet credit card transaction, or the distribution of confidential files by dishonest employees may result in devastating losses to the company. United States legislation has addressed cybercrime in the Computer Fraud and Abuse Act of 1986, in which it is a felony to obtain information to which a person is not entitled through the unauthorized access or exceeded authorization. Still, nationwide United States Attorneys have been slow to prosecute those corporate insiders who violate the Computer Fraud and Abuse Act of 1986.
Whether facilitated by dishonest or merely careless employees, the misappropriation and compromise of sensitive files has caused significant disruptions among businesses in the global business community. Notwithstanding, corporate insiders operating as professional thieves can be even more elusive than and destructive than merely dishonest or careless employees. Many studies have concluded that competitors, disgruntled employees and independent hackers alike are intent upon stealing sensitive corporate information at any opportunity.
Government agencies, law firms, investment banks, accounting and auditing firms and engineering organizations are particularly sensitive to the unauthorized appropriation of sensitive data. In particular, it is of paramount concern to protect the contents of electronic versions of legal agreements, proposals, functional and technical specifications and technical drawings. Yet, many have a tendency to ignore threats to sensitive data until after the sensitive data has been misappropriated.
Tampering or theft of sensitive files is not the only concern for those who manage files in the enterprise. Business electronic mail (e-mail) usage continues to grow at an astounding rate. It is clear that e-mail has become a critical mode of inter and intra-business communications. Nevertheless, every transmitted e-mail and corresponding e-mail attachment can result in an unintentional breach of security. In particular, when a party other than the intended recipient of the e-mail accesses the e-mail, the intent of a secure transaction has been lost.
Several products have been developed in recent times to address the problem of securing files from unintentional or malicious misappropriation. For example, Authentica, Inc. of Waltham, Mass. (Authentica) has developed a system for securing sensitive electronic files, even after those sensitive files have been distributed to selected recipients. More particularly, in the Authentica system sensitive files can be encrypted and access policies including digital rights applied thereto prior to transmitting the file to a recipient.
Once an encrypted file has been received, the recipient can access a central server to assist the recipient in decrypting the encrypted file. Of course, the server also can ensure that the recipient has access privileges which satisfy the access policies of the sensitive file. Finally, the digital rights included with the encrypted file can ensure that the recipient does not exceed the recipient's authority to modify or further distribute the sensitive file.
Still, inasmuch as the Authentica solution is a client/server solution, the Authentica system requires that the recipient maintain a network connection to the central server when the recipient attempts to access an encrypted file. Thus, the Authentica system lacks flexibility. Furthermore, the Authentica solution is not transparent in that accessing a file protected using the Authentica system requires substantial user interaction and the deployment of a separate application. Specifically, to enforce the digital rights associated with a protected file, for example whether a user can modify, copy, or print the file, the Authentica system utilizes a separate file viewer. The use of a separate file viewer, however, can inhibit the transparency necessary to conduct effective file collaboration.
Infraworks Corporation of Austin, Tex., by comparison, has developed a server-independent solution in which file security can be managed by a client-side plug-in containing all necessary logic to control access to an attached file. Developed to specifically address the security of e-mail distributed files, the Infraworks solution, however, lacks the ability to secure collaborative files which are not necessarily distributed via e-mail. For instance, the Infraworks solution cannot secure a collaborative file accessed over a network through the conventional file-open dialog box of a word-processor. Moreover, the Infraworks solution, like the Authentica solution, lacks the transparency required to effectively promote file collaboration.
Importantly, file collaboration has become an important element of inter and intra-business activities. Specifically, it has become a common occurrence for corporate competitors to intentionally collaborate with one another using commonly accessible files, despite the sensitivity of the contents of those files. In fact, in many cases competitors and corporate partners alike exchange sensitive files via e-mail and e-mail attachments. File collaboration also can result in the unintentional modification or destruction of a commonly shared file. In particular, in the collaborative environment, it is not uncommon for collaborators to accidentally lose or destroy electronic files.
In many cases, those who would engage in file collaboration may do so in the presence or absence of network facilities. Specifically, often it can be desirable to access a secure file while disengaged from a network, such as while traveling or while at home. In consequence, in a collaborative environment, those who intentionally disseminate sensitive data also must track and enforce limitations on the use and further dissemination of the sensitive data, regardless of the availability of a centralized server configured to control such limitations on the use and further dissemination of the sensitive data. Furthermore, the enforcement of such limitations must occur transparently so as to promote effective, yet seamless file collaboration.

Collaborative file access management system


Photo film (15) has pairs of perforations (21) arranged at a regular pitch (L1+L2). A photo film advancing device for advancing the photo film by the regular pitch (L1+L2) has a take-up spool (23), which winds the photo film after each exposure. A rotatable sprocket wheel (26, 68, 80, 83, 90) has a circular peripheral face (27, 71, 80c, 87, 93) with first and second teeth. The first (25a, 68a, 80a, 85b, 91a) and second teeth (25b, 68b, 80b, 85a, 91b) engage the respective perforations. A wind stop claw (36a) locks the sprocket wheel to prevent the photo film from advancing when the first and/or second perforation is engaged with the first and/or second tooth. The wind stop claw unlocks the sprocket wheel when a shutter (44) operates. While unlocked, the sprocket wheel is rotated a small amount by advancement of the photo film, to move the second tooth away from the second perforation. The peripheral face of the sprocket wheel frictionally contacts the photo film. Then the first tooth contacts the photo film to stand by to engage the succeeding first perforation. While the first tooth stands by, the photo film is advanced in contact with the first tooth.

1. Field of the Invention
The present invention relates to a sprocket wheel and a photo film advancing device. More particularly, the present invention relates to a sprocket wheel for use with a photo film in which each of frames is associated with two perforations regularly, and a photo film advancing device for advancing the photo film.
2. Description Related to the Prior Art
A lens-fitted photo film unit, as known in the art, is pre-loaded with unexposed photo film and incorporates a photo film advancing device. The photo film advancing device has a construction in which a sprocket wheel is rotated by movement of photo film, and adapted to charging a shutter. Such a photo film advancing device is also utilized in a simplified camera of a low-cost type. In view of the photo film of a 135 type having eight perforations per frame, the sprocket wheel in the photo film advancing device has eight teeth. Upon advancement of the photo film as much as eight perforations, the sprocket wheel makes one rotation. Thereupon, a manually operable winding wheel is stopped from rotating, to stop the photo film. In the course of the one frame feeding, the shutter is charged. In the photo film advancing device, the advancement of the photo film is mechanically detected by use of the perforations. Only a simple structure can detect the one frame feeding exactly. At least one of the teeth of the sprocket wheel is engaged with a train of the perforations, so that the photo film advancing device can receive relatively high drive force from the photo film. It is possible with reliability to charge the shutter while displacing a spring.
U.S. Pat. No. 5,471,265 (corresponding to JP-A (Japanese Patent Laid-open Publication No.) 5-19368) discloses a photo film in which each frame is associated with two perforations. One of the two is associated with an edge of the frame nearer to the leader. The other of the two is associated with an edge of the frame nearer to the trailer. Each frame is created between positions of the two perforations. The perforations are arranged at two intervals which are alternately repeated. The longer of the two intervals is related to a length of each frame. The shorter of the two intervals is related to an interval between two adjacent frames.
To detect the one frame feeding of the photo film of this type, it is conceivable to monitor passage of the perforations through a photo sensor to stop of the photo film. One of every two of the perforations may be detected photoelectrically. Optionally each pair of perforations may be detected photoelectrically. However, such techniques are unsuitable for a compact camera of a low-cost type, because complicated circuits for amplifying and rectifying a photoelectric signal from the photo sensor would be required as well as the photo sensor.
It is also conceivable to use a detector claw used in a 110 camera of a simple type. The detector claw may be biased by a spring, and mechanically shifted to move into each perforation. When the detector claw enters a perforation at an edge of each frame nearer to the trailer, one frame feeding of the photo film can be detected. This can be detected also upon movement as far as a regular length after entry of the detector claw into a perforation. However, a shortcoming lies in that a mechanism is inevitably required for removing the detector claw from the perforations. Such a removing mechanism, with its excessively complicated linkages, is likely to operate erroneously. Another disadvantage lies in efficient use of interior space, because the claw must be moved perpendicularly to the movement of the photo film.

Sprocket wheel and photo film advancing device


A phase shifter includes a first signal path in which a first unit is disposed to advance a phase of a signal; a second signal path in which a second unit with no shunt capacitor is disposed to change the phase of the signal such that the changed phase is delayed than the advanced phase by the first unit; and a switch section configured to switch between the first signal path and said second signal path. The first unit comprises a filter, and the second unit is a transmission line.

1. Field of the Invention
The present invention relates to a phase shifter and a bit phase shifter using the same. This Patent Application claims priority based on Japanese Patent application No. 2007-021725. The disclosure of the Japanese Patent application is incorporated herein by reference.
2. Description of Related Art
The phased array technique has been used for special purposes such as a radar and is used in commercial products in recent years. Application of the technique is further considered to receive satellite broadcasting. A phase shifter is indispensable to use of the phased array technique. In accordance with extension of application fields of the phased array technique, a demand is increasing for an inexpensive phase shifter suitable for commercial products and a satisfactory phase shifter having excellent high-frequency performance and suitable for receiving satellite broadcasting. However, it is difficult in a conventional phase shifter to satisfy requirement for the inexpensive phase shifter and requirement for the phase shifter with excellent high-frequency performance.
As a switching type of phase shifter used in a microwave band, an HPFLPF (high pass filter and low pass filter) switching type of phase shifter, or a switched line type of phase shifter are known. Japanese Patent No. 2679331 (first conventional example) describes a representative example of the HPFLPF switching type of phase shifter, and Japanese Laid Open Patent Application (JP-A-Heisei 7-38304) (second conventional example) describes a representative example of the switched line type of phase shifters.
FIG. 1 is a circuit diagram of an HPFLPF switching type of phase shifter. Referring to FIG. 1, the HPFLPF switching type of phase shifter includes an input-side SPDT (single pole double throw) switch 100, an HPF (high pass filter) 110, an LPF (low pass filter) 112, and an output-side SPDT switch 102.
The input-side SPDT switch 100 has an FET (field effect transistor) F10 connected to a first signal path, and an FET F11 connected to a second signal path. In the input-side SPDT switch 100, control voltages are applied to a control terminal CON 10 and a control terminal CON11 in a complementary manner, respectively. That is, an OFF voltage is applied to the control terminal CON11 when an ON voltage is applied to the control terminal CON10, and the ON voltage is applied to the control terminal CON11 when the OFF voltage is applied to the control terminal CON10. Accordingly, the FET F11 is in an off state when the FET F10 in an on state, and the FET F11 is in an on state when the FET F10 is in an off state.
The output-side SPDT switch 102 has an FET F12 connected to the first signal path, and an FET F13 connected to the second signal path. In the output-side SPDT switch 102, control voltages are applied to a control terminal CON12 and a control terminal CON13 in a complementary manner, respectively. Since an OFF voltage is applied to the control terminal CON13 when an ON voltage is applied to the control terminal CON12, the FET F13 is in an off state when the FET F12 is in an on state. Moreover, the ON voltage is applied to the control terminal CON13 when the OFF voltage is applied to the control terminal CON12, so that the FET F13 is in an on state when the FET F12 is in an off state.
The same control voltages are applied to the control terminal CON10 of the input-side SPDT switch 100 and the control terminal CON12 of the output-side SPDT switch 102. Accordingly, the FET F12 of the output-side SPDT switch 102 is turned on when the FET F10 of the input-side SPDT switch 100 is turned on. At this time, the first signal path is selected. The same control voltages are also applied to the control terminal CON11 of the input-side SPDT switch 100 and the control terminal CON13 of the output-side SPDT switch 102. Accordingly, the FET F13 of the output-side SPDT switch 102 is turned on when the FET F11 of the input-side SPDT switch 100 is turned on, and in this case the second signal path is selected.
The HPF 110 is disposed in the first signal path. The HPF 110 has a shunt inductor L10 connected to a ground, and two series-connected capacitors C10 and C11 are disposed to put the inductor L10 between them. On the other hand, the LPF 112 is disposed in the second signal path. The LPF 112 has a shunt capacitor C12 connected to a ground, and two series-connected inductors L11 and L12 are disposed to put the capacitor C12 between them.
When the ON voltages are applied to the control terminal CON10 and the control terminal CON12, and when the OFF voltages are applied to the control terminal CON11 and the control terminal CON13, a signal is inputted from an input terminal IN10 and is outputted from an output terminal OUT10 via the HPF 110. At this time, the signal passes through the HPF 110, and thereby the phase is advanced. Meanwhile, when the OFF voltages are applied to the control terminal CON10 and the control terminal CON12, and when the ON voltages are applied to the control terminal CON11 and the control terminal CON13, the signal inputted from the input terminal IN10 is outputted from the output terminal OUT10 via the LPF 112. At this time, the signal passes through the LPF 112 and thereby its phase is delayed.
In the HPFLPF switching type of phase shifter, the signal path connected to the HPF 110 and the signal path connected to the LPF 112 are switched by the SPDT switches 100 and 102, so that a phase shift amount corresponding to a phase difference between the two signal paths can be obtained. An arbitrary phase shift amount can be obtained by selecting the capacitors C10, C11 and C12 and the inductors L10, L11 and L12 to constitute the HPF 110 and the LPF 112, respectively. In a designed frequency band, a phase is advanced on an HPF 110 side, and the phase is delayed on an LPF 112 side. For example, if it is designed so that the phase on the HPF 110 side is advanced by 22.5 degrees and the phase on the LPF 112 side is delayed by 22.5 degrees at the designed frequency band, a phase shift amount of 45 degrees can be obtained.
FIG. 2 is a block diagram showing a configuration of another conventional phase shifter which is generally called a switched line type of phase shifter. Referring to FIG. 2, the switched line type of phase shifter includes an input-side SPDT switch 104, a first transmission line 120, a second transmission line 122, and an output-side SPDT switch 106.
In FIG. 2, when ON voltages are applied to a control terminal CON14 and a control terminal CON16, and when OFF voltages are applied to a control terminal CON15 and a control terminal CON17, an FET F14 and an FET F16 are turned on, and an FET F15 and an FET F17 are turned off. At this time, a signal is inputted from an input terminal IN11 and is outputted from an output terminal OUT11 via the transmission line 120. Meanwhile, when the OFF voltages are applied to the control terminal CON14 and the control terminal CON16, and when the ON voltages are applied to the control terminal CON15 and the control terminal CON17, the FET F14 and the FET F16 are turned off, and the FET F15 and the FET F17 are turned on. At this time, the signal is inputted from the input terminal IN11 and is outputted from the output terminal OUT11 via the transmission line 122.
The signal paths are operationally switched through on/off control of the SPDT switches 104 and 106 in the same manner as in the circuit shown in FIG. 1. In the switched line type of phase shifter, a phase difference between the two signal paths can be obtained as a phase shift amount. The transmission lines 120 and 122 having different lengths are connected to the respective signal paths, and in this case, the difference between phases of the signals due to different line lengths is utilized. Since the both of the signal paths have phase delays, it is assumed that the transmission line 120 has a length to delay the phase by 10 degrees in the designed frequency band, and the transmission line 122 has a length to delay the phase by 55 degrees. At this time, the phase shift amount of 45 degrees can be obtained.
As described above, a pair of HPF 110 and LPF 112 is used in the HPFLPF switching type of phase shifter and a pair of the transmission lines 120 and 122 having different lengths is used in the switched line type of phase shifter. Other phase shifters used in a millimeter wave band include a known phase shifter described in Japanese Patent Application Publication (JP-A-Heisei 11-195960) (third conventional example). The phase shifter described in the third conventional example relates to a phase shifter in a millimeter wave band in which SPDT switch characteristics cannot be obtained, so that a signal switch is not used. Thus, it is different from phase shifters of the HPFLPF switching type and the switched line type used in a microwave band. It should be noted that since many quarter-lines (four lines at minimum) are used in the phase shifter in the third conventional example, a chip size is increased. Therefore, it is extremely difficult to fabricate an inexpensive phase shifter.
A phase shifter can be configured by using either one of the conventional phase shifters, i.e. the HPFLPF switching type of phase shifter or the switched line type of phase shifter, without having any problems in the most cases. However, problems arise depending on a specific frequency band to be used and a phase shift amount.
If the phase shift amount is made smaller in the HPFLPF switching type of phase shifter, a phase shift amount advanced in a HPF and a phase shift amount delayed in an LPF need to be made smaller. In order to decrease the phase shift amounts of the filters, capacitors and inductors to constitute the filters need to have small constants. The LPF is configured of the series of inductors and the shunt capacitor, in which constants of these elements are made smaller in case of decreasing the phase shift amount. However, it is not possible in the shunt capacitor to ignore effect of a parasitic inductance caused by extending a wiring pattern in a high frequency band. Therefore, it is difficult to use small capacitance of a shunt capacitor. In order to realize a small capacitance of the shunt capacitor, problems arise such as increase of factors to process variations and increase of a phase shift error. Accordingly, frequency characteristics need to be sacrificed to some extent in case of the HPFLPF switching type of phase shifter having a small phase shift amount for the high frequency band.
Meanwhile, in the case of the switched line type of phase shifter, a large difference in the line length is required for a large phase shift amount. Accordingly, there are drawbacks such as arrangement of a long transmission line and an increased chip size. As a result, the cost increases. An influence of the larger line difference on frequency characteristics of a phase shifter increases.
The above problems occur in both the HPFLPF type of phase shifter and the switched line type of phase shifter, when a phase shift amount is set to be 20 to 45 degrees in the frequency band of about 10 to 15 GHz. Therefore, either frequency characteristics or costs are sacrificed in the conventional phase shifters.

Phase shifter having switchable signal paths where one signal path includes no shunt capacitor and inductor


A multidirectional switch (1) comprises an insulative housing (2), a first fixed contact (31) and a third fixed contact (33), a first moveable contact (41) and a second moveable (42) contact disposed above the first fixed contact (31) and the third fixed contact (33), an operation member (5) mounted on the first moveable contact (41) and defining a second pressing portion (53). The second pressing portion (53) presses the second moveable contact (42) in order to make the second moveable contact (42) contact with or separate from the third fixed contact (33). The first moveable contact (41) always contacts with the first fixed contact (31). The second moveable contact (42) is integrated with the first moveable contact (41) and distributed around the first moveable contact (41).

1. Field of the Invention
The present invention relates to a miniature multi-directional switch, and particularly to a multidirectional switch used in consumer electronic applications.
2. Description of the Prior Art
The personal electronic consumer productions such as cell phones are designed to comply with a miniature trend as the customers require. Correspondingly, electronic elements such as switches employed in those productions are required to be miniature.
A conventional multidirectional switch 10′ is disclosed in FIG. 4 comprises an insulative housing 1′, a first fixed contact (23′, 24′, 25′, 26′), a common contact 22′, a second fixed contact 21′, a first moveable contact 3′, a second moveable contact 5′, an operation member 6′ and a cover 7′. The first fixed contact (23′, 24′, 25′, 26′), a common contact 22′ and the second fixed contact 21′ are disposed on the bottom surface 11′ of the housing 1′. The first moveable contact 3′ is attached on the operation member 6′ and moves together which comprises a constant contacting portion and a moveable contacting portion, wherein the constant contacting portion 51′ always abuts against the common contact 22′. The second moveable contact 21′ is disposed above the second fixed contact 21′ and the common contact 22′ and comprises a center portion 31′ and a fringe portion 32′, wherein the fringe portion 32′ comes into contact with the common contact 22′. The operating portion 6′ is disposed above the second moveable contact 21′ and comprises a first pressing portion 63′ and a second pressing portion. The housing 1′ and the cover 7′ cooperatively contain the first fixed contact (23′, 24′, 25′, 26′), the second fixed contact 21′, the first moveable contact 3′, the second moveable contact 5′ and the operating member 6′ therein. When pressing the operating member 6′ perpendicularly, the second pressing portion presses the second moveable contact 5′ downwardly, which make the second moveable contact 5′ contact or separate with the second fixed contact 21′. When pressing the operating portion 6′ in a slant direction, the first pressing portion 63′ presses the moveable contacting portion 52′ of the first moveable contact 3′, which makes the moveable contacting portion 52′ contact or separate with the first fixed contact (23′, 24′, 25′, 26′). Hence, the multidirectional switch 10′ can realize the control function thereof.
However, the first moveable contact 3′ is separated with the second moveable contact 5′, which makes the manufacturing process of the multidirectional switch 10′ more complicate. In addition, the moveable contact with bigger size can lead to a bigger size of the whole multidirectional switch, which is not desired.
Hence, an improved multidirectional switch is required to overcome the disadvantages of the prior art.


Illuminated poster frame with a frame box including a front frame, side panels and a rear panel, the frame box including a front clear panel. The top panel of the frame box has a slit to removably retain an inner frame that houses a poster. The inner frame has a front frame portion and a rear frame portion to removably retain the poster. The poster is printed on transparent of translucent material capable of transmitting light so that the entire poster is illuminated. The inside of the frame box includes a formed sheet having a plurality of recesses that each retains an amber LED. A translucent sheet placed in front of the LED holding sheet diffuses the light emanating from the LED's. A power source such as a battery supply or a wall pack transformer powers the LED's.

This invention relates generally to the field of picture frames and more specifically to an illuminated poster frame.
Posters for movies or TV shows have become a popular form of art and are often framed for hanging on a wall. The posters come in a variety of sizes and include black and white images and well as full color images. In particular, posters that depict images or characters from children's movies or TV shows have become popular items to decorate a child's room.
A deficiency in the current methods of displaying posters is that they can not be seen in a darkened room. They also are difficult and time consuming to remove from a frame so that they may be replaced by another poster.


Embodiments include methods and apparatus associated with wireless multicast and/or broadcast services. A base station (102, FIG. 1) transmits data codes (504, 604, 702, FIGS. 5-7) within a radio frame (300, FIG. 3). The data codes are Code Division Multiple Access (CDMA) data codes, in an embodiment. The base station also transmits a Time Division Multiplexed (TDM) synchronization code (502, 608, 706, FIGS. 5-7), in an embodiment. The base station discontinuously transmits (1004, FIG. 10) a portion of a radio frame slot that is coincident in time with a duration of the TDM synchronization code, in various embodiments. The discontinuously transmitted portion of the radio frame slot may include Transport Format Combination Indicator (TFCI) bits (510, FIG. 5), pilot bits (710, FIG. 7), or data bits (612, FIG. 6), in various embodiments. A base station's transmissions may be synchronous in time and frequency with the transmissions of other base stations.

Various wireless communications networks offer features or specifications aimed at the efficient delivery of multimedia or other data formats on a multicast or broadcast basis. These networks include Universal Mobile Telecommunications System (UMTS) wideband Code Division Multiple Access (WCDMA) networks, which may be specified by 3GPP (3rd Generation Partnership Project), 3GPP2, ETSI (European Telecommunications Standards Institute), and/or the Institute of Electrical and Electronics Engineers (IEEE).
For example, an IEEE 802.16e specification defines a Multicast Broadcast Service (MBS), which exploits "single frequency networking" (SFN) principles to deliver service (e.g., mobile television) on an efficient, wide area basis. In an SFN network, multiple transmitters simultaneously send the same signal over the same frequency channel. High levels of spectral efficiency may be achieved for a broadcast or multicast service by simulcasting, on a fully time-synchronous and frequency-synchronous basis, shared Medium Access Control (MAC) layer Protocol Data Units (PDUs) using a common or identical set of radio resources in each cell. This may provide high orders of downlink macro-diversity (e.g., where multiple base stations transmit the same signals), which when combined with a lack of in-band interference, may lead to elevated receiver Signal-to-Noise Ratios (SNRs). These techniques may be capable of supporting relatively high modulation orders and forward error correction encoding rates.
In some systems, SFN techniques are associated with Orthogonal Frequency Division Multiplexing (OFDM) methods of wireless network multiple access. Other air interface specifications, such as the 3GPP2 Broadcast and Multicast Services (BCMCS) feature, seek to hybridize OFDM and CDMA approaches to air interface design by multiplexing components of a legacy CDMA air interface and an OFDM-based broadcast network on a Time Division Multiplexing (TDM) basis. For example, SFN methods may be applied to direct sequence CDMA networks, as exemplified by a 3GPP specification entitled "A Backward Compatible CDMA-Based Enhanced Broadcast Multicast (EBM) System for HRPD," 3GPP2 Technical Specification Group C, October 2004, C30-20041019-011.
Techniques for broadcast and multicast service delivery are also defined for networks based solely on CDMA principles in the absence of SFN methods. For example, the Multimedia Broadcast Multicast Service (MBMS), as part of the 3GPP Release-6 specifications, uses diversity techniques, such as soft symbol combining or selection combining for efficient transfer of data (e.g., multimedia content) to multiple user equipments (UEs) in a point-to-multipoint fashion. Methods of downlink macro-diversity that are based on soft combining or selection combining techniques generally may not be able to approach the receiver SNR's achievable using SFN methods.
Another proposal entitled "Dedicated MBMS Carrier Using Common Transmitted Waveforms," 3GPP TSG-RAN WG1 Meeting #46, August 2006, R1-062268 (herein "R1-062268"), applies an SFN approach to the 3GPP MBMS service. Specifically, R1-062268 proposes that only an orthogonal primary common control physical channel (P-CPICH) and one or more secondary common control physical channel (S-CCPCH) be transmitted by each participating base station (BS), in a time-synchronous and frequency-synchronous fashion, in a downlink spectrum cleared of interfering unicast transmitters or other radiators (e.g., the downlink spectrum is dedicated to MBMS). R1-062268 also proposes that each BS scramble its transmission using a common scrambling code. This approach may permit higher receiver SNRs to be achieved, and generally may improve wide-area broadcast channel spectrum efficiency However, this approach suffers from at least three major drawbacks.
First, according to R1-062268, primary synchronization channel (P-SCH) and secondary synchronization channel (S-SCH) symbols are not transmitted on the dedicated MBMS carrier frequency. Due to the lack of a synchronization channel on the dedicated MBMS carrier, UEs are forced to camp on, and extract synchronization information from, a companion unicast network. This may be inefficient and time-consuming, and may render redundant significant components of established and high performance UE P-SCH and S-SCH acquisition hardware.
A second drawback pertains to an argument, in R1-062268, that current wireless CDMA (or WCDMA) receiver architectures can deal with the increased channel time dispersion resulting from SFN operation without a major re-working of the receiver design. However, the increase in delay spread in networks with contemporary cell radii does not support this argument. Third, channel estimation using a code-division multiplexed pilot signal (e.g., a pilot signal based in the P-CPICH symbol) is susceptible to significant intra-cell interference in multi-path channels. This may be more pronounced in the case of an SFN channel with its increased median root mean square (RMS) delay spread, and may warrant further modification or enhancements of the current 3GPP Common Pilot Channel (CPICH) structure.
It is desirable to provide a solution that enhances the achievable receiver SNR of current wireless multicast and/or broadcast air interface designs (e.g., the 3GPP WCDMA Release-6 MBMS). In addition, it is desirable to provide a solution that does not warrant the deployment of additional synchronization equipment in BSs, and that permits UEs to access a dedicated enhanced MBMS carrier without having to access a companion unicast network. Additionally, it is desirable to provide a solution that enables sufficient channel estimation SNR to sustain higher spectrum efficiency in the broadcast service. In addition, it is desirable that a 3GPP MBMS specification evolution permit substantial re-use of existing terminal designs.
Other desirable features and characteristics of the present inventive subject matter will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background.

Wireless multicast broadcast service methods and apparatus


Disclosed is a method and apparatus which provides for alerting of potential fiber optic cable intrusion. A stress detector located at a fiber optic cable termination point detects stress on the fiber optic cable and generates an alarm signal in response to the stress detection. The alarm signal is transmitted to remote alarm units along the fiber optic right of way via a conductive metallic portion of the fiber optic cable (e.g., the fiber optic cable sheath). In response to receipt of an alarm signal, the alarm units initiate a perceptible (e.g., audible and/or visible) alarm. The stress detector may also determine a location of the stress, and generate an alarm signal addressed to a particular one or more alarm units in the vicinity of the stress location.

The present invention relates generally to optical fiber intrusion systems, and more particularly to providing local area warning of optical fiber intrusion.
Recent years have seen a proliferation of telecommunication services. With the additional services has come an increased need for network infrastructure, including in particular, buried cables and associated equipment. One type of cable is fiber optic cable, which generally contains multiple optical fibers bundled together within one cable.
Fiber optic cable is subject to damage, especially when buried close to the surface or when located in the vicinity of a construction site. Since a single fiber optic cable may carry a very large amount of data, the failure of a single fiber optic cable may result in service outage for a large number of customers. As such, network service providers take precautions in order to avoid such failure.
One technique for monitoring buried fiber optic cable is disclosed in U.S. Pat. No. 5,778,114, entitled Fiber Analysis Method and Apparatus. That patent describes a fiber intrusion detection system for detecting an intrusion or potential intrusion to a buried fiber optic cable. That system includes an optical splitter for splitting an optical signal into sub-signals for injection into opposite ends of a looped optical fiber. The signals emanating from the opposite fiber ends are recombined at the splitter for receipt at a detector that measures the phase difference between the optical sub-signals. A processor compares the phase difference measured by the detector to known phase difference measurements associated with different types of threats. By matching the actual phase difference to the known phase difference measurement associated with a particular type of intrusion, the processor can thus identify the nature of the intrusion.
While detecting the fiber intrusion threat is important, in order to avoid actual damage to a fiber optic cable, it is also important to warn the potential intruder of the imminent threat. However, an alarm at a central network location may not allow for network provider personnel to reach the actual threat location (e.g., construction site) in time to avoid the damage. In recognition of this problem, the '114 patent discloses a disturbance monitor that may be dispersed along the right-of-way of the fiber optic cable for providing a visible and/or audible warning in the field in response to a signal from the fiber intrusion detection system. The '114 patent discloses a wireless link between the fiber intrusion detection system and the disturbance monitor for signaling an alarm condition. One disadvantage of that configuration is that a wireless communication link may not always be available, or such a link may provide an unreliable communication channel.

Local area warning of optical fiber intrusion


A piezoelectric thin film sensor array is used to scan and capture biometric data, for example, a fingerprint image. In one embodiment, a multi-layer structure includes a PVDF layer in between two conductor grids arranged orthogonally to one another. Urethane can be added to one side where a finger is placed. A foam substrate can be used as a support. In one feature, the PVDF, and grids can be peeled off like a label for easy replacement. Multiplexers are switched to scan the sensor. A single pixel or a group of pixels can be detected and output to an image memory. The presence of a fingerprint ridge is detected by virtue of a ring-down oscillation that arises from reflection when an electric field is applied to the piezoelectric thin film sensor array at a pixel in contact with the fingerprint ridge. For example, such a ring-down value associated with a fingerprint ridge can be detected at about 150 ns. (or 5 cycles at 30 MHZ). Other reflections indicative of additional biometrics (e.g. from tissue, blood, bone, fingernail, etc.) can also be detected. A Doppler effect due to reflections from circulating blood can also be detected. Such a Doppler effect can provide further information about direction and speed of blood circulation. An instantaneous pyroelectric effect can also be detected to indicate a live finger presence.

1. Field of the Invention
The present invention relates generally to fingerprint scanning and imaging. More specifically, this invention relates to a piezoelectric film used within a fingerprint scanner.
2. Related Art
Biometrics are a group of technologies that provide a high level of security. Fingerprint capture and recognition is an important biometric technology. Law enforcement, banking, voting, and other industries increasingly rely upon fingerprints as a biometric to recognize or verify identity. See, Biometrics Explained, v. 2.0, G. Roethenbaugh, International Computer Society Assn. Carlisle, Pa. 1998, pages 1–34 (incorporated herein by reference in its entirety). A number of companies are currently active in biometric finger technologies. See, a listing of companies published by Biometric Technology Today (Btt™), two pages, 1999 (http://www.sjbresearch.com).
Optical fingerprint scanners are available that detect a reflected optical image of a fingerprint. To capture a quality image at a sufficiently high resolution, optical fingerprint scanners require at minimum optical components (e.g., lenses), an illumination source, and an imaging camera. Such components add to the overall cost of a fingerprint scanner. Mechanical structures to maintain alignment also increase manufacturing and maintenance costs.
Solid-state silicon-based transducers are also available in commercial fingerprint scanners sold by Seimens, Lucent, and Harris Semiconductor. Such silicon transducers measure capacitance. This requires the silicon transducers to be thin, reducing their durability. To detect a rolled fingerprint, the sensing array of the solid-state transducer needs to have an area of sufficient size, for example one-inch by one-inch with a thickness of about 50 microns. A silicon array with such a large size increases the base cost of a fingerprint scanner and leads to greater maintenance costs. Durability and structural integrity are also more likely to suffer in such a large silicon geometry.
What is needed is an inexpensive, durable fingerprint scanner with low maintenance costs.


A thermostatic subcooling control valve is disclosed which is capable of enhancing evaporative power of an evaporator in a refrigerating cycle to thereby improve refrigerating capacity of the refrigerating cycle and which is capable of ensuring safety from danger of a high pressure refrigerant and which is capable of attaining improved precision and improved reliability. The thermostatic subcooling control valve according to the present invention comprises a valve body having a pressure-operative portion and a valving element operating portion for sensing temperature and pressure of a refrigerant to operate, and the valve body is contained in a casing provided with a refrigerant inlet connecting portion and a refrigerant outlet connecting portion. Preferably, the casing comprises an entrance casing member having the inlet connecting portion and an exit casing member having the outlet connecting portion, and the casing members are fixedly joined together to thereby contain the valve body.

1. Field of the Invention
The present invention relates to a thermostatic subcooling control valve. In particular, it relates to a thermostatic subcooling control valve which senses degree of supercooling (subcooling) of a refrigerant in a refrigerating cycle to control a flow rate of the refrigerant.
2. Description of the Prior Art
Heretofore, a thermostatic expansion valve has generally been used as a flow rate control valve of this type for a refrigerant in a refrigerating cycle. To carry out flow rate control of the refrigerant, heating degree of the evaporated refrigerant at an outlet of an evaporator is sensed by a temperature sensing element and, based on the sensing, the thermostatic expansion valve is operated.
The thermostatic expansion valve is designed, as described above, to have function of controlling the heating degree of the evaporated refrigerant at the outlet of the evaporator to within a predetermined temperature range. Accordingly, no matter how the heating degree of the refrigerant is controlled by the thermostatic expansion valve, it is impossible to attain increase in capability of the evaporator in the refrigerating cycle. In other words, the thermostatic expansion valve is designed to control the heating degree, and hence it has no function of enhancing capability in terms of improvement in refrigerating efficiency.
Further, the thermostatic expansion valve insufficient in terms of safety of the refrigerating cycle. Specifically, for example, even if pressure of the refrigerant in a high pressure-exposed portion in the refrigerating cycle becomes extraordinarily high to incur dangerous condition, the thermostatic expansion valve has no function of protecting an appliance disposed in a high pressure line in the refrigerating cycle from the extraordinarily high pressure because it is not so constructed as to operate based on the pressure in the high pressure-exposed portion in the refrigerating cycle.
To solve the above-described drawbacks of the thermostatic expansion valve, it has been proposed that a subcooling control valve is disposed downstream from a refrigerant condenser in a refrigerating cycle to control degree of supercooling (subcooling) of a high pressure refrigerant.
FIG. 3 shows one form of such a known subcooling control valve. The subcooling control valve 50 comprises a substantially cylindrical valve body 51 and a pressure responsive member 52 located on the top of the valve body 51. The pressure responsive member 52 is divided by a diaphragm 53 into an upper compartment 54 and a lower compartment 55. The valve body 51 comprises an upper valve chamber 56 and a lower valve chamber 57, and the upper valve chamber 56 and the lower valve chamber 57 are in communication with each other via a throttle 58 serving as a valve seat. The upper valve chamber 56 is unified with and in communication with the lower compartment 55 of the pressure responsive member 52.
The upper valve chamber 56 provided with a refrigerant inlet 59 in communication with a condenser, and the lower valve chamber 57 is provided with a refrigerant outlet 60 in communication with an evaporator. To the lower surface of the diaphragm 53, one end of a valve stem 61 is fixedly attached. To the other end of the valve stem 61, a valving element 62 is fixedly attached. The valving element 62 is suspended in the throttle 58, and a compression spring 63 is disposed under the valving element 62 to always bias the valving element 62 upward.
A refrigerant line 64 is located downstream from the refrigerant condenser and upstream to the refrigerant inlet 59 of the subcooling control valve 50, and thereon, a temperature sensing element 65 is placed in contact therewith for detecting a temperature of the refrigerant in the line 64. The temperature sensing element 65 is in communication with the upper compartment 54 of the pressure responsive member 52 via a capillary tube 66. The temperature sensing element 65, the capillary tube 66 and the upper compartment 54 are hermetically filled with a refrigerant, and change in the temperature of the refrigerant flowing in the line 64 in the refrigerating cycle is sensed by the temperature sensing element 65 to act on the diaphragm 53 of the pressure responsive member 52 as change in pressure.
Displacement of the valving element 62 of the subcooling control valve 50 relative to the throttle 58 is controlled according to balance of the pressure exerted on the diaphragm 53 by the upper compartment 54 of the pressure responsive member 52 via the capillary tube 66 on the basis of the temperature sensing by the temperature sensing element 65 versus the pressure in the line 64-the lower compartment 55 of the pressure responsive member 52 and the force of the compression spring 63 which are exerted on the diaphragm 53. According to the displacement of the valving element 62, opening degree of the throttle 58 is determined to thereby control flow rate of the refrigerant passing through the subcooling control valve 50.
In the conventional subcooling control valve 50 constructed as described above, however, it is required that the temperature sensing element 65 for sensing degree of supercooling of the refrigerant flowing downstream form the refrigerant condenser be provided separately from the valve body structure of the subcooling control valve 50 and that the capillary tube 66 be employed for communication between the temperature sensing element 65 and the subcooling control valve 50. Accordingly, in installation operation of the subcooling control valve 50 and the temperature sensing element 65 in the refrigerating cycle, it is inconvenient to place the subcooling control valve 50 and the temperature sensing element 65 at proper positions. In addition, there is undesired possibility of troubles such as breakage of the capillary tube 66 due to inaptitude in handling.
Further, the capillary tube 66 is made of a small-diameter tube and thus likely to undergo blockage during use for some reason to cause a situation where the subcooling control valve 50 is put out of action.
Moreover, the subcooling control valve 50 is so constructed that the temperature change of the refrigerant flowing downstream from the refrigerant condenser in the refrigerating cycle is sensed by means of the temperature sensing element 65 and the temperature change is exerted as pressure change of the refrigerant in the temperature sensing element 65 on the diaphragm 53 of the upper compartment 54 of the pressure responsive member 52 placed at a distance from the temperature sensing element 65 via the capillary tube 66. Accordingly, the subcooling control valve 50 has problems that delay is likely to occur in the response, and that since the temperature sensing element 65 is placed in contact with the refrigerant line 64 in the refrigerating cycle, it is difficult to precisely sense the temperature change of the refrigerant in the refrigerating cycle.
Furthermore, the lower compartment 55 of the pressure responsive member 52 exerts the pressure of the refrigerant in the lower compartment 55 on the diaphragm 53, whereas the upper compartment 54 transforms the temperature of the refrigerant in the line 64 located upstream to the lower compartment 55 into pressure and exerts the pressure on the diaphragm 53. In other words, the diaphragm 53 in the pressure responsive member 52 is operated not based on the temperature and pressure of the refrigerant at the same position but based on the temperatures and pressures of the refrigerant at the different positions in the course of flow. Accordingly, the subcooling control valve disadvantageously tends to have poor sensing and operating accuracy and thus to lack reliability.


In the installation of a position measuring device it is necessary that parameters such as amplitude and phase position of the analog scanning signals as well as the position of the reference mark signal are tested. In order to accomplish such testing, a control device is provided that has a display field for visually indicating these parameters. A first bar is displayed in the display field and its width represents a measure for the fluctuation range of the radius and its position represents a measure for the average radius of a Lissajous figure. In addition, a marking is displayed for permissible fluctuation in range of this radius. Furthermore, a second bar is displayed in the display field, which indicates the position of the reference mark signal in relation to the analog signals generated by the scanner.

It is particularly important to test the signals generated by a scanner of a position measuring device in order to correctly install the scanner in the position measuring device. It is well known to provide a position measuring device having a scanner and scale to determine the position of a movable part, such as a machine, relative to a fixed part. Typically, the scanner outputs two signals in quadrature. These outputs can be input to further circuitry for counting the cycles of the incoming signals so as to determine position, to determine the direction of movement, and to provide position interpolation within one cycle of the output. It is desirable that the scanner be correctly installed relative to the scale so that the output signals from the scanner are accurately in quadrature with a 90.degree. phase shift and have substantially the same amplitude. Signal quality and the precision of measurement depends greatly on the correct installation of the scanner relative to the scale. The amplitude of the signals generated by the scanner is influenced by the distance between the scanner and scale and the phase shift is influenced by the tilt of the scanner relative to the direction of measurement.
With incremental measuring systems, in addition to the incremental division, a reference mark or marks is placed on the scale. When the reference mark is scanned, an analog reference mark signal is generated which defines the reference mark's position. As a rule, with the appearance of the maximum of the reference mark signal, a stored absolute reference position is assumed by a counter and this assumed value is continuously updated by the incremental position measuring occurring during the relative movement between the scale and the scanner. Because an incremental counting step is only a fraction of a period of the scale, it is particularly important that the reference mark signal is associated as favorably as possible with a particular counting step, i.e., fraction of the period. This association is influenced considerably by the angular orientation of the scanner.
In order to test the correct installation of the scanner relative to the scale it is known to display the amplitude and phase shift of the analog signals generated by a scanner on an oscilloscope. The two analog signals output by the scanner are input to two channels of a double beam oscilloscope so that a Lissajous figure is generated. The radius of the Lissajous figure is a measure of the amplitudes as well as the phase relation of the analog signals. If the scanner is perfectly positioned with respect to the scale, the Lissajous figure will be a perfect circle centered at the origin.
In order to simplify the testing of the signals generated by a scanner, U.S. Pat. No. 5,128,609 discloses a control device having a bar display. In this control device, a radius of the Lissajous figure is calculated from the instantaneous amplitudes of the analog signals generated by a scanner and the instantaneous radius value is represented as a lighted point on the bar display. While this control device is easier to handle than an oscilloscope, the bar display does not provide sufficient resolution to allow one to make fine adjustments in the scanner's position.
During the installation of a scanner relative to a scale, the amplitudes of the analog signals generated by the scanner can range from zero to a maximum of, for example, 12 .mu.A. This relatively large range must be able to be displayed in order for the analog signals to be tested. However, because of space limitations displaying such a large range compromises the resolution of the display. This has the disadvantage that the range of variation of the radius of the Lissajous figure cannot be represented with sufficient resolution and precision since the instantaneous radius value appears only as a single lighted point. In addition, there is no disclosure of testing a reference mark signal.
The RENISHAW company sells a control device for testing position-dependent scanning signals. This control device with the name RGSUE has features according to U.S. Pat. No. 5,128,609 described above. Furthermore, this control device has a display field for indicating the position of a reference mark. In the operating instructions, it is explained that the detection of the reference mark can be checked using the display. An adjusting screw is provided for adjusting the position of a reference mark. When the position of the reference mark is correctly adjusted, a green LED is illuminated on the display; when the position of the reference mark is incorrectly adjusted, a yellow or red LED is illuminated. This control device has the disadvantage that its ability to assist the operator in adjusting the scanner particularly during installation is insufficient. This disadvantage also applies to the device described in U.S. Pat. No. 5,241,173.
An object of the present invention is to provide a control device and a process for testing position-dependent analog signals where the parameters of the analog signals can be displayed with sufficiently high resolution and precision in order to make an adjustment of the scanning head easier for the operator.
An advantage of the present invention is that important parameters of the analog signals can be better recognized and thus, in a simple way, a good quality of analog signals can be obtained. Furthermore, the adjustment of the scanner is made easier during installation by virtue of the fact that the direction in which the scanning head should be moved and pivoted is also displayed.

Control device and process for testing position-dependent signals of a position measuring device


A display device having high definition and high reliability, and technology for manufacturing the same. In an active matrix type display device of integrated peripheral driving circuit type, pixel TFTs of an active matrix circuit 100 are not provided with LDD regions. Also, among circuits constituting peripheral driving circuits 101, 102, buffer circuits, of which a high withstand voltage and high-speed operation are required, are made with thin film transistors having floating island regions and base regions between source and drain regions of their active layers.

This invention relates to a display device comprising semiconductor devices in which crystalline thin film semiconductor are used, and a method for manufacturing the same. More particularly, the invention relates to an active matrix type liquid crystal display device.
A liquid crystal display device is an image display device having a structure wherein a liquid crystal layer is held between a pair of glass substrates and having a function of modulating visible light passing through the liquid crystal layer by applying an electric field to the liquid crystal layer and thereby causing its optical characteristics to change.
This electric field causing the optical characteristics of the liquid crystal layer to change is formed between pixel electrodes and common electrodes, and desired gradation display can be carried out by the amount of charge entering and leaving each pixel electrode being controlled according to an image signal.
To achieve this, recently the active matrix circuit type display device has become a representative of next-generation displays and has been being researched and developed vigorously.
An active matrix type display device is a device wherein a thin film transistor (TFT) is provided in each of as many as several million pixels arrayed in the form of a matrix, and charges entering and leaving pixel electrodes of the pixels are controlled by means of a switching function of the TFTs.
The pixel TFTs (these multiple pixel TFTs will be referred to collectively as an active matrix circuit) are controlled by circuit TFTs disposed in peripheral driving circuit areas formed at sides of a pixel area. The circuit TFTs constitute different types of circuit such as buffer circuits and shift register circuits according to how they are combined.
That is, an active matrix type display device is a construction wherein pixel TFTs disposed in a matrix in a pixel area and circuit TFTs disposed in peripheral driving circuit areas are all integrated on the same substrate.
However, at present in active matrix type liquid crystal display devices, unevenness occurring and stripe patterns appearing in displays is a problem. In particular, these stripe patterns are extremely harmful to the visual appearance of displayed images.
As a result of carrying out extensive research into display defects appearing as stripe patterns forming when a display device is driven, the present inventors have ascertained that a cause of these defects lies in LDD regions formed in the active layers of the pixel TFTs. Reasons for this are as follows.
In making active matrix type liquid crystal display devices, crystalline silicon films are generally used for the active layers of the thin film transistors. These crystalline silicon films are usually obtained by crystallizing amorphous silicon films.
As the crystallizing means, excimer laser annealing, which has the merit that it is possible to carry out crystallization at a low temperature, is widely used. Crystallization by laser annealing is carried out by irradiating with a laser beam formed into the shape of a line or into a rectangular shape. It is known that generally it is difficult to obtain uniform crystallinity in crystalline silicon films crystallized by laser annealing.
Also, silicon film in a molten state pushed between crystal grains instantaneously growing becomes a solid in a state wherein it has risen just like a wave. When this happens, these parts can be observed as ridges in the surface of the crystalline silicon film obtained.
Thus the crystallinity and the surface condition of a crystalline silicon film obtained by laser annealing vary greatly over the face of the substrate.
When an LDD region is formed, the crystallinity of the crystalline silicon film is disordered by impurity ions being implanted into it and the film temporarily becomes non-crystalline. At this time, due to influences such as those of the above-mentioned differences in crystallinity and differences in the probability of ridges being present, dispersion in the impurity ion concentration arises.
As a result of this, when activation of the impurity ions and recrystallization of the silicon film is carried out by laser annealing, reflecting the above-mentioned dispersion in crystallinity and dispersion in the impurity ion concentration due to the presence of ridges, dispersion arises in the sheet resistance of the LDD regions.
That is, dispersion caused by laser annealing directly has a large affect on dispersion in the sheet resistance of the LDD regions. This dispersion in the sheet resistance of the LDD regions corresponds to dispersion in the on-current of the operating TFTs.
When this dispersion in on-current is large, the accumulation of charge to the pixel electrode is insufficient in some pixels and desired image display becomes impossible. The problem has also arisen that since dispersion in on-current influences the amount of charge accumulated to the pixel electrodes, the pixel electrode holding voltage level changes according to the dispersion in on-current, and it is not possible to obtain desired gradation display.
On the other hand, in circuit TFTs, of which high-speed operation and high output are required, because deterioration due to heat production and hot carriers becomes a serious problem, LDD regions have inevitably been indispensable.
Consequently, when pixel TFTs and circuit TFTs are made TFTs of the same structure, as in Japanese Laid-Open Application 1-289917, LDD regions have always been formed in the pixel TFTs also.
That is, when TFTs having the same structure are used in all the circuits (the active matrix circuit and the peripheral driving circuits), when the requirements of the peripheral driving circuits are considered importance is inevitably attached to deterioration resistance and LDD regions are therefore provided, but in turn this has resulted in dispersion in the on-current of the pixel TFTs and constituted a cause of display defects such as stripe patterns.
There has also been the problem that when LDD regions are disposed in circuit TFTs of buffer circuits, of which a high withstand voltage of about 16V is required, their operating speed falls and the circuit characteristics deteriorate.

Display device having a switch with floating regions in the active layer

Semiconductor Energy Laboratory Co., Ltd.


A base module having a cylindrical female socket mates with a cylindrical cartridge plug connected to the electrical fixture. The base socket contains at least three circular or annular electrical contact strips, which are electrically connected to at least hot, neutral and ground wires of the building's circuitry. The male cartridge plug, which is configured to be rotatably insertable into the female base socket, contains at least three spring-loaded pop-up electrical contacts, each of which engages one of the base contact strips and remains continuously so engaged through a full 360° rotation of the cartridge plug. The plug's pop-up contacts are electrically connected, through the plug casing, to at least the hot, neutral and ground terminals of the electrical fixture. Rotational adjustments of the fixture are accommodated by rotating the cartridge plug within the base socket. Two spring-loaded locking arms on the plug are configured to releasably engage the base socket so as to fix the rotational orientation of the fixture once it has been adjusted. The cartridge plug is mechanically connected to the fixture through a cartridge mount, which is configured to enable and secure translational adjustments in the position of the fixture.

Among the deterrents to changing or adding electrical fixtures, such as lighting sconces and ceiling fans, in residential and commercial buildings are the difficulty and expense of installing the requisite wiring. Consumer installation of such fixtures is fraught with perils, including electrical shock and fire hazards. On the other hand, employment of professional electricians can be prohibitively expensive.
These difficulties could be minimized by a pre-wired universal electrical fixture mounting base with a twist-and-lock mechanism by which a variety of appliances could be energized without the need for hard-wiring. The present invention is designed to provide such a permanent electrical mounting system.


The removable plug features a solid material that is housed in a porous container that has its shape changed to transition from the run in shape to the set shape. A swage is moved through a passage in the container to enlarge the passage and move the container to a borehole wall. The passage is then closed such as with a flapper valve or by moving in a mandrel into the expanded passage and lodging the mandrel in the expanded passage. Various release techniques are described.

Zones in a wellbore have been isolated from each other with sand plugs. Typically, a porous substrate is supported in the wellbore and sand is pumped onto the substrate. Pressure is applied and the sand is dewatered. If a long enough sand column is created, the pressure applied from pumped fluid above forces the sand particles together in such a manner as to create a barrier to isolate zones in a wellbore from each other. When the barrier is no longer needed a jetting tool at the end of coiled tubing or the like is run into position above the plug. The jetting action and the circulation starts to work on the compacted sand pile and eventually allows the particles to come off the cohesive plug and get lifted from the well with the circulating fluid that exits the jetting nozzles. Some examples of this technique are U.S. Pat. Nos. 5,623,993 and 5,417,285. Other efforts in horizontal wells involve recipes of a variety of granular components that have predetermined properties such as specific gravity below 1.25 to create the plug using deposition techniques. One example of this is U.S. Pat. No. 7,690,427.
Other designs place swelling material in porous enclosures and allow the swelling action to create relative movement that allows a packer to go from a run in to a set position as overlapping petals of swelling material in enclosures rotate relatively to reach a sealing configuration in a borehole. This technique is illustrated in U.S. Pat. No. 7,422,071.
What is needed and provided by the present invention is a plug that can be set with a setting tool that creates relative movement and features a solid granular material in a porous enclosure where the setting action alters the shape of the enclosure to attain the set position. This can be done by bringing one end closer to another end and preferably through a passage in an annularly shaped sheath. Alternatively a swage can be brought through a passage in an annularly shaped sheath to enlarge the passage and in so doing set up the fill material in the sheath to push against the surrounding wellbore while a valve such as a flapper closes the passage to pressure from above. The porous enclosure can then be undermined in a variety of ways to allow the granular material to escape where it can be removed with fluid circulation. In some variations, a mandrel allows flow therethrough until an object is landed on a seat for zonal isolation. In other instances the mandrel can be undermined as a way of letting the granular material escape. The retaining porous material can be dissolved or in other ways removed so that it will not interfere with the working of other tools in the borehole. For fracturing plug purposes, perfect sealing is not required as long as sufficient flow past the plug is sufficiently slowed so that the acting pressure can deliver the requisite flow into the fractures to further open them, in the known manner. The use of a mandrel can also be optional and the plug structure can comprise a granular material in a porous enclosure that folds on itself to set. An optional lock feature or a valve to prevent reverse flow in the setting location when relative movement occurs can also be incorporated. These and other features can be incorporated into the design as will be more readily apparent to those skilled in the art from review of the details of the description of the preferred embodiment and the associated drawings, while understanding that the full scope of the invention is to be determined from the appended claims.

Removable fracturing plug of particulate material housed in a sheath set by expansion of a passage through the sheath


The present invention provides a method to start a steady state process for producing normally gaseous, normally liquid and optionally normally solid hydrocarbons from synthesis gas, which method comprises the steps of: (i) providing an activated catalyst in tubes of a fixed bed reactor, preferably a multitubular fixed bed reactor, the catalyst being suitable to convert synthesis gas to normally gaseous, normally liquid and optionally normally solid hydrocarbons; (ii) contacting the activated catalyst with a liquid to obtain a wetted activated catalyst; (iii) contacting the wetted activated catalyst with synthesis gas and catalytically converting the synthesis gas at an elevated temperature and pressure to obtain the normally gaseous, normally liquid and optionally normally solid hydrocarbons.

Many documents are known describing processes for the catalytic conversion of (gaseous) hydrocarbonaceous feedstocks, especially methane, natural gas and/or associated gas, into liquid products, especially methanol and liquid hydrocarbons, particularly paraffinic hydrocarbons. In this respect often reference is made to remote locations and/or off-shore locations, where no direct use of the gas is possible. Transportation of the gas, e.g. through a pipeline or in the form of liquefied natural gas, is not always practical. This holds even more in the case of relatively small gas production rates and/or fields. Reinjection of gas will add to the costs of oil production, and may, in the case of associated gas, result in undesired effects on the crude oil production. Burning of associated gas has become an undesired option in view of depletion of hydrocarbon sources and air pollution.
The Fischer-Tropsch process can be used for the conversion of synthesis gas (from hydrocarbonaceous feed stocks) into liquid and/or solid hydrocarbons. Generally, the feed stock (e.g. natural gas, associated gas and/or coal-bed methane, heavy and/or residual oil fractions, coal, biomass) is converted in a first step into a mixture of hydrogen and carbon monoxide (this mixture is often referred to as synthesis gas or syngas). The synthesis gas is then fed into a reactor where it is converted in one or more steps over a suitable catalyst at elevated temperature and pressure into paraffinic compounds ranging from methane to high molecular weight compounds comprising up to 200 carbon atoms, or, under particular circumstances, even more.
Numerous types of reactor systems have been developed for carrying out the Fischer-Tropsch reaction. For example, Fischer-Tropsch reactor systems include fixed bed reactors, especially multi-tubular fixed bed reactors, fluidised bed reactors, such as entrained fluidised bed reactors and fixed fluidised bed reactors, and slurry bed reactors such as three-phase slurry bubble columns and ebullating bed reactors.
The Fischer-Tropsch reaction is very exothermic and temperature sensitive, with the result that careful temperature control is required to maintain optimum operation conditions and desired hydrocarbon product selectivity. Indeed, close temperature control and operation throughout the reactor are major objectives.
Starting up such a process will involve new and regenerated catalyst material. However, catalyst material when new is often more active than when it has achieved a steady state activity under reaction conditions. In chemical reactions such as the Fischer-Tropsch reaction, which is very exothermic and temperature sensitive as mentioned above, a higher level of activity of a catalyst at the start up of a reactor is a significant concern.
There is thus required a way of using the initial greater activity of new catalyst material until the reaction process reaches a steady state. Several start-up procedures have been proposed in the prior art to cope with the initial greater activity of the catalyst.
In WO 03/068715 for example is described a process for starting up a Fischer-Tropsch slurry reactor wherein an initial charge of molten wax is established in a Fischer-Tropsch reactor. The reactor contains a portion of its steady state catalyst inventory in contact with the molten wax. The catalyst is supplied to the reactor in the form of a slurry of molten wax and catalyst particles. The reactor preferably contains clean molten wax without catalyst particles and a slurry of molten wax and catalyst particles is then mixed with the clean wax. At start-up, syngas at a flow rate below the steady state flow rate and a H2/CO ratio above the steady state ratio is contacted with the catalyst at a temperature below the steady state temperature.
In WO 2005/026292 and WO 2005/026293 is disclosed a method for start-up of a hydrocarbon synthesis process in a slurry bubble column. The start-up method comprises a specific procedure for charging the catalyst particles via a charging vessel into the conversion reactor. At the end of the charging phase, the reactor is kept at a temperature ranging from 150 to 220° C. and a pressure ranging from 1 to 10 bar and is continuously fed with inert gas to prevent catalyst sedimentation. During a conditioning phase, the temperature is brought to values suitable for conditioning, the inert gas is gradually substituted by synthesis gas up to a concentration ranging from 5-50 vol % and this concentration is maintained for 24-72 hours. Then, the pressure and temperature are gradually increased up to steady state regime values and the concentration of inert gas gradually reduced to zero.

Method to start a process for producing hydrocarbons from synthesis gas


An image pickup apparatus, an image pickup method and a non-transitory computer readable recording medium are provided. The image pickup apparatus includes an image sensor including a first pixel group and a second pixel group, a controller which controls the image sensor to capture an image of an object by using the first pixel group and to capture a live view of the object by using the second pixel group, a storage which stores the image captured by the first pixel group, and an auto focusing (AF) processor which generates AF information by using the live view captured by the second pixel group.

1. Field
Apparatuses, methods, and media consistent with the present disclosure relate to an image pickup apparatus, a method for image pickup, and a computer-readable recording medium, and more specifically, to an image pickup apparatus which acquires auto focusing information promptly and precisely, a method for image pickup, and a computer-readable medium.
2. Description of the Related Art
Recently, digital cameras are being developed which enhance the quality of the velocity and the preciseness of auto focusing (AF) and which include a smaller and lighter main case to meet the consumer's demands.
However, because the image sensor of the conventional camera cannot acquire the precise AF information of an object during consecutive image pickup (capture) operations, the image pickup apparatus needs to stop at every image pickup operation to collect the precise AF information. Further, because the conventional camera cannot acquire and display the current information of the object in single or consecutive image pickup operations, the displaying operation is stopped to acquire the information.
In addition, to acquire the AF information of the object, a conventional method of acquiring phase differential AF information detects the phase differential information using a shielding device to shield a part of pixels of an image sensor. However, this method has a shortcoming in that the pixel information of the original image is lost.
Thus, a new image sensor is necessary, which can acquire the AF information without compromising pixels of an original image, while displaying the live view image in consecutive image pickup operations.

Image pickup apparatus, method for image pickup and computer-readable recording medium


The present invention relates to a wet start-up method for hydrogenation unit, an energy-saving hydrogenation process, and a hydrogenation apparatus. The method involves heating a start-up activating oil to a specific temperature and flowing the heated oil through a bed of hydrogenation catalyst bed, so that the temperature at the catalyst bed layer is increased to 180±10° C. or above by means of heat exchange and the reaction heat generated from activation in the start-up method.

As environmental protection laws and regulations become stringent increasingly, the demand for clean light fuels is more and more. Hydrogenation technology is an effective means for production of clean products; therefore, hydrogenation units have become standard equipment in oil refineries, and more and more hydrogenation units are used in oil refining enterprises.
The technical core of hydrogenation units lies in the application of hydrogenation catalysts. The hydrogenation function of hydrogenation catalysts comes from active metals, which are usually classified into noble metals and non-noble metals. Non-noble metals are usually used, mainly including VIB and VIII groups of metal elements (e.g., Mo, W, Ni, and Co, etc.). These metals usually exist in oxidation state in commercial hydrogenation catalysts. Metals and metal atoms in oxidation state have low hydrogenation performance, and they will exhibit high hydrogenation performance only after they are converted into sulfurized state. Therefore, to attain best hydrogenation performance of a hydrogenation catalyst, the catalyst must be sulfurized before used. Hydrogenation catalysts can be classified into sulfurized type catalysts (a sulfurizing agent is introduced into the catalyst, but the active metals are not converted into sulfurized state completely) and sulfurized-state catalysts (the active metals are converted into sulfurized state completely).
The hydrogenation process usually has to be carried out at a high temperature. During start-up process of a hydrogenation unit, the unit must be heated up from normal temperature to a higher temperature (usually ≧300° C.). Hydrogenation units are usually equipped with a heating furnace to provide heat during the start-up process and normal production process of the units. Hydrogenation reactions are usually strong exothermic reactions. In the normal production process of a hydrogenation unit, the outlet temperature of the reactor is much higher than the inlet temperature of the reactor. Thus, the materials can be heated by heat exchange without any heating furnace. However, during start-up process, since the normal hydrogenation reaction hasn't started yet, there is no heat source for heating up the unit; moreover, a heating furnace is required during start-up process since the required temperature can't be reached if any device other than a heating furnace is used. The heating furnace is a high temperature and high pressure device in the hydrogenation unit and it accounts for a large part of the equipment investment. Moreover, the heating furnace is only used during start-up process, and has a very low utilization ratio.
Patent document CN200910188142.4 discloses a sulfurizing agent supply method for wet sulfurization process of catalyst, which is mainly used for start-up process of liquid circulating hydrogenation units. With that method, a heating furnace is required. Patent document CN 200510047487.X discloses a start-up method for FCC gasoline hydro-desulfurization and olefin reduction. That method mainly utilizes reformate as sulfurized oil and can avoid the temperature rise in the sulfurization process, it is only applicable to gasoline hydrogenation units that contain zeolite catalysts.
Patent document U.S. Pat. No. 5,688,736 discloses a catalyst sulfurization method, but that method strictly forbids the use of olefin-containing start-up oil during start-up process. Patent documents CN200910188114.2, CN200910204266.7, CN200810010242.3, CN200810010245.7, CN200910204248.9, and CN200910204249.3 disclose start-up methods for hydrogenation units that utilize a sulfurized type catalyst, but those methods require an activating oil with low olefin content during start-up process, and the heat required for heating up the reaction system in the catalyst activation process has to be provided by a heating furnace. Patent document CN200910204283.0 "Start-up Method for Residual Oil Hydrotreating Process" discloses a start-up method for hydrogenation units that contain a partially sulfurized type hydrogenation guard catalyst, but the heat has to be provided by a heating furnace during start-up process.
For start-up process of hydrogenation unit that utilize a sulfurized type hydrogenation catalyst, the method that is used mostly is to introduce a start-up activating oil at low temperature and heat up the unit at a specific heating rate, till the temperature is close to the reaction starting temperature of the feedstock; then, the activating oil can be replaced by the feedstock by steps. However, a heating furnace is required during start-up process to provide the heat required for heating up the reaction system, and the energy consumption during start-up process is heavy. For units that are not equipped with a heating furnace, the start-up process can not be accomplished with that method. In addition, the system pressure drop will be increased severely and the energy consumption will be increased severely if a heating furnace is used, owing to the complex internal structure of the heating furnace.

Wet start-up method for hydrogenation unit, energy-saving hydrogenation process and hydrogenation apparatus

Fushun Research Institute of Petroleum and Petrochemicals, SINOPEC


A water-closet disposable pouch (8) has a pull-away tab (20) secured to one wall (10) by a weld or bond (22). Pulling away the tab (20) tears open the pouch wall (10) along the weld or bond by tearing out material (30) from the weld, thus creating one or more gaps (28). The tab (20) may be V-shaped, and define a flap or hatch area (26) of the wall behind the tab (20) which is released when the tab (20) is torn away. Any gas trapped in the pouch can escape through the opening when the gas is placed in a WC. In an alternative form, a tear-out filament is secured to or within a wall of the pouch parallel to a direction of orientation of the plastics material.

This invention relates to a water-closet (WC) disposable pouch.
As is well known, there have been continuing efforts to design a satisfactory WC-disposable pouch. Such pouches are worn by those who have suffered a surgical diversion operation such as a colostomy. One example of such a pouch is shown in European Patent Application No. 10171B (H. Kiefer), and others in GB 2 083 762B, GB 2 227 668 and GB 2 227 937. EP 272,816 discloses a pouch which has an integral tear strip embedded in its front or rear panel laminate. Despite a variety of approaches, no known pouch design has consistently met the requirements of easy manipulation and consistent WC-flushability. One intractable problem is that air trapped in the pouch causes it to fail to pass around the U-bend of a conventional water-closet.
The present invention has been devised bearing the above problems in mind.


A first continuous query is deleted from several continuous queries that are being executed, by performing different actions that depend on how resources are shared therebetween. As an example, a second continuous query is deleted if a view is referenced by the first continuous query, and if the view is built on the second continuous query, and if the view is not referenced by any query other than the first continuous query. Such deletion is followed by compiling the second continuous query, followed by updating the view to refer to a newly-compiled version of the second continuous query. As another example, if an operator in the first continuous query is not used by any other query, this operator is de-scheduled from execution, and any exclusively-owned resources are released. Also, data to be read by the operator and data generated by the operator, if present in shared resources, are deleted therefrom.

It is well known in the art to process queries over data streams using one or more computer(s) that may be called a data stream management system (DSMS). Such a system may also be called an event processing system (EPS) or a continuous query (CQ) system, although in the following description of the current patent application, the term "data stream management system" or its abbreviation "DSMS" is used. DSMS systems typically receive a query (called "continuous query") that is applied to a stream of data that changes over time rather than static data that is typically found stored in a database. Examples of data streams are: real time stock quotes, real time traffic monitoring on highways, and real time packet monitoring on a computer network such as the Internet. FIG. 1A illustrates a prior art DSMS built at the Stanford University, in which data streams from network monitoring can be processed, to detect intrusions and generate online performance metrics, in response to queries (called "continuous queries") on the data streams. Note that in such data stream management systems, each stream of data can be infinitely long and hence the amount of data is too large to be persisted by a database management system (DBMS) into a database.
As shown in FIG. 1B a prior art DSMS may include a query compiler that receives a query, builds an execution plan which consists of a tree of natively supported operators, and uses it to update a global query plan. The global query plan is used by a runtime engine to identify data from one or more incoming stream(s) that matches a query and based on such identified data to generate output data, in a streaming fashion.
Continuous queries (also called "persistent" queries) are typically registered in a data stream management system (DSMS), and can be expressed in a declarative language that can be parsed by the DSMS. One such language called "continuous query language" or CQL has been developed at Stanford University primarily based on the database query language SQL, by adding support for real-time features, e.g. adding data stream S as new data type based on a series of (possibly infinite) time-stamped tuples. Each tuple s belongs to a common schema for entire data stream S and the time t increases monotonically. Note that such a data stream can contain 0, 1 or more pairs each having the same (i.e. common) time stamp.
Stanford's CQL supports windows on streams (derived from SQL-99) which define "relations" as follows. A relation R is an unordered group of tuples at any time instant t which is denoted as R(t). The CQL relation differs from a relation of a standard relational model used in SQL, because traditional SQL's relation is simply a set (or bag) of tuples with no notion of time, whereas the CQL relation (or simply "relation") is a time-varying group of tuples (e.g. the current number vehicles in a given stretch of a particular highway). All stream-to-relation operators in CQL are based on the concept of a sliding window over a stream: a window that at any point of time contains a historical snapshot of a finite portion of the stream. Syntactically, sliding window operators are specified in CQL using a window specification language, based on SQL-99.
An example to illustrate continuous queries is shown in FIGS. 1C-1E. Specifically, FIG. 1E illustrates a merged STREAM query plan for two continuous queries, Q1 and Q2 over input streams S1 and S2. Query Q1 is shown in FIG. 1C expressed in CQL as a windowed-aggregate query: it maintains the maximum value of S1:A for each distinct value of S1:B over a 50,000-tuple sliding window on stream S1. Query Q2 shown in FIG. 1D is expressed in CQL and used to stream the result of a sliding-window join over streams S1 and S2. The window on S1 is a tuple-based window containing the last 40,000 tuples, while the window on S2 is a 10-minutes time-based window.
Several DSMS treat queries as fixed entities and treat event data as an unbounded collection of data elements. This approach has delivered results as they are computed in near real time. However, in most continuous query systems known to the current inventors, the standard approach doesn't allow a continuous query to be deleted dynamically. One reason known to the current inventors is that a query plan is computed at the time of registration of all queries, before the DSMS begins operations on streams of event data. To the knowledge of the current inventors, once the queries have registered and the DSMS begins to process event data, the query plan cannot be changed. The current inventors note that queries can be made to appear as deleted, if a DSMS is programmed to drop the output of queries being deleted, but such appearance is misleading because system load remains unchanged, if deleted queries are still executed.

Deleting a continuous query from a data stream management system continuing to operate on other queries


In an energy recovery circuit of a plasma display panel, after storing energy in the inductor, the panel capacitor is charged by using a resonance and the stored energy. A first time period during which energy is stored in the inductor before discharging the panel capacitor is longer than a second time period during which energy is stored in the inductor before charging the panel capacitor, so that a voltage higher than half of the sustain-discharge voltage is charged to the energy recovery capacitor. In addition, the first time period of the case in which the load ratio is low is shorter than the first time period of the case in which the load ratio is high, so that the thermal stress applied to the energy recovery circuit may be reduced.

1. Field of the Invention
The present invention relates to a driving method of a plasma display panel (PDP), and a plasma display device. More specifically, the present invention relates to an energy recovery circuit of the PDP.
2. Background Description
A PDP is a flat panel display that uses plasma generated by gas discharge to display characters or images. It includes, depending on its size, more than several scores to millions of pixels arranged in a matrix pattern. Such a PDP is classified as a direct current (DC) type or an alternating current (AC) type according to its discharge cell structure and the waveform of the driving voltage applied thereto.
The DC PDP has electrodes exposed to a discharge space to allow DC to flow through the discharge space while the voltage is applied, and thus requires a resistance for limiting the current. To the contrary, the AC PDP has electrodes covered with a dielectric layer that forms a capacitor to limit the current and protect the electrodes from the impact of ions during discharge. Thus, the AC PDP generally has a longer lifetime than the DC PDP.
FIG. 1 is a partial perspective view of an AC PDP.
Pairs of scan electrodes 4 and sustain electrodes 5 are arranged in parallel on a first glass substrate 1 and are covered with a dielectric layer 2 and a protective layer 3. On a second glass substrate 6, a plurality of address electrodes 8 covered with an insulating layer 7 are arranged. Barrier ribs 9 are formed in parallel with the address electrodes 8 on the insulating layer 7, which is interposed between the address electrodes 8. A fluorescent material 10 is formed on the surface of the insulating layer 7 and on both sides of the barrier ribs 9. The first and second glass substrates 1 and 6 are arranged face-to-face with a discharge space 11 formed therebetween, and the scan electrodes 4 and the sustain electrodes 5 lie normal to the address electrodes 8. The discharge space at the intersection between the address electrode 8 and the pair of scan electrode 4 and sustain electrode 5 forms a discharge cell 12.
FIG. 2 shows an arrangement of electrodes in the PDP.
The PDP has a pixel matrix consisting of mxn discharge cells (or pixels). In the PDP, address electrodes A1 to Am are arranged in columns, and scan electrodes Y1 to Yn and sustain electrodes X1 to Xn are alternately arranged in rows. The discharge cell 12 shown in FIG. 2 corresponds to the discharge cell 12 in FIG. 1.
In general, a single frame is divided into a plurality of subfields, and the subfields are driven in the AC PDP. Each subfield includes a reset period, an address period, and a sustain period with respect to temporal operation variations.
The reset period is for initiating the status of each cell to facilitate the addressing operation. The addressing period is for selectively turning cells on and off and applying an address voltage to the turned on cells (i.e., addressed cells) to accumulate wall charges. The sustain period is for applying sustain pulses and causing a sustain-discharge for displaying an image on the addressed cells.
The discharge spaces between the scan and sustain electrodes and between the address electrode side and the scan/sustain electrode side act as a capacitance load (hereinafter, referred to as "panel capacitor"), so capacitance exists on the panel. Due to the capacitance of the panel capacitor, a reactive power is needed so as to apply a waveform for the sustain-discharge. Thus the PDP driver circuit includes a power recovery circuit for recovering the reactive power and reusing it.
An example of such a power recovery circuit is described in U.S. Pat. Nos. 4,866,349 and 5,081,400 issued to L. F. Weber.
This circuit repeatedly transfers energy of the panel to a power recovery capacitor or transfers energy stored in the power recovery capacitor to the panel using a resonance between the panel capacitor and the inductor, thus recovering the effective power. In this circuit, however, the rising/falling time of the panel voltage is dependent upon the time constant LC determined by the inductance L of the inductor and the capacitance C of the panel capacitor. The rising time of the panel voltage is equal to the falling time because the time constant LC is constant. For a faster rising time of the panel voltage, the switch coupled to the power source has to be hard-switched during the rise of the panel voltage, in which case stress on the switch increases. The hard-switching operation also causes a power loss and increases the effect of electromagnetic interference (EMI).

Plasma display device and driving method of plasma display panel