A polycrystalline body includes aluminum oxide, magnesium oxide, zirconium oxide, and lutetium oxide. The lutetium oxide is present in an amount of at least 10 ppm of the weight of the ceramic body, and the magnesium and zirconium oxides are present at a molar ratio of from 0.5:1 to 3:1.

The present invention relates generally to polycrystalline alumina ceramics. It finds particular application in connection with an alumina ceramic composition which is doped with zirconia, magnesia, and lutetia, which is suited to formation of a discharge vessel for a lamp and will be described with particular reference thereto.
Discharge tubes for high intensity discharge (HID) lamps, and in particular, high pressure sodium (HPS) lamps have been fabricated from a variety of translucent alumina materials, including polycrystalline alumina and single crystalline alumina (sapphire). The discharge tube includes a fill of light-emitting elements, such as sodium and mercury, and a starting gas, such as argon. When the lamp is energized, an arc discharge forms with a characteristic emission spectrum which is related to the particular composition of the fill.
The life of such sodium lamps is frequently limited by the loss of the sodium portion of the fill during lamp operation by diffusion of sodium ions through the wall of the discharge tube. The lost sodium is then unavailable to the arc discharge and can no longer contribute its characteristic emissions, causing the light output to gradually diminish, and causing the color to shift from white towards blue. In addition, the arc becomes more constricted, and in a horizontally operated lamp, the arc may bow against and soften the arc chamber wall. Sodium loss may also cause the operating voltage of the lamp to increase to the point where the arc can no longer be sustained by the ballast and failure of the lamp may result.
Ceramics doped with magnesium oxide and used in lamps have been shown to be susceptible to darkening the outer jacket when lamps are operated at wattages above the design space of the ceramic arc tube. Darkening of the glass outer jacket has been linked to a combination of evaporation of the ceramic arc chamber and sodium loss through the walls of the arc tube due to reaction and diffusion mechanisms. This can limit lumen output and the useful life of the lamp. In addition to the sodium diffusion, the sodium in the arc can react with the alumina at the grain boundaries to form sodium aluminate, which adversely affects the structural integrity of the tube and shortens lamp life. Discharge lamps are being designed for ever increasing internal sodium partial pressure within the alumina arc tube to improve the color rendition and provide a whiter emitted light. However, higher internal sodium pressure further shortens lamp life due to increased rate of sodium loss from the arc chamber. Progressive sodium loss results in a corresponding continual rise in the lamp operating voltage, a decrease of both correlated color temperature and color rendering index, and a color shift from white to pink. Also, the sodium which migrates through the arc chamber wall deposits on the inside wall of the evacuated outer lamp envelope causing a brownish stain on the envelope which, in turn, further reduces the light output of the lamp.
The manufacture of polycrystalline alumina (PCA) and single crystal alumina (sapphire) HPS arc discharge lamps is known. U.S. Pat. Nos. 3,026,210; 4,150,317 and 4,285,732 to Coble, Alaska et al., and Charles et al., respectively, disclose the production of a high density alumina body having improved visible light transmission using relatively pure alumina powder and small amounts of magnesia.
It is desirable for lamps to have a high efficiency to reduce power consumption. A need exists for an alumina arc tube having a reduced tendency to permit sodium diffusion which also provides high transmission of light.

Translucent polycrystalline alumina ceramic


A sealing device (100) includes a resinous sealing ring (110) and an elastomeric elastic ring (120) in an annular groove 210. The sealing ring (110) has a cylindrical surface portion (112a) making intimate contact with a groove bottom of the annular groove (210) and an inclined surface portion (112b) expanding in diameter toward the atmosphere side (A). The elastic ring (120) is disposed such that at least its portion is compressed between the inclined surface portion (112b) and the groove bottom of the annular groove (210) so as to press a portion of the sealing ring (110) on the atmosphere side (A) toward the outer peripheral side.

A sealing device is provided on a portion of a cylinder head of an engine where an injector is attached to in order to prevent high-pressure combustion gas from leaking through an annular gap between an attachment hole formed in the cylinder head and the injector. Moreover, a sealing device is similarly provided on a portion of the cylinder head where sensors and so forth are attached to. In such a sealing device, a technique that employs a resinous sealing ring that has a smaller number of components and can better suppress noise from vibration, when compared with the case of using a metal washer-like sealing, is known.
However, the resinous sealing ring has a problem that a compressing margin on an outer peripheral side decreases with time due to creep deformation and hence its sealing performance eventually deteriorates. In order to solve such a problem, techniques that employ a structure in which a self-sealing function is exerted due to the pressure of combustion gas or a structure in which a surface pressure is partially increased are known (see Patent Literatures 1, 2, and 3). Although such techniques can extend the life span to some degree, it cannot be said that those techniques can sufficiently suppress deterioration of the sealing performance due to a continuing decrease in the compression margin. In particular, countermeasures against the deterioration of the sealing performance due to a loss of compression margin and in low-temperature, low-pressure condition are not sufficient.
Moreover, a technique of suppressing deterioration of the sealing performance by providing an elastic member on an inner peripheral side of a resinous sealing ring that presses the sealing ring toward an outer peripheral side is also known (see Patent Literature 4). However, in this technique, the elastic member is directly exposed to combustion gas. It is, therefore, required to use a material having high heat resistance for the elastic member, and there is another problem that the function of the elastic member deteriorates. Accordingly, there is still room for improvement.


Compositions and methods for bone health, cartilage health or both, are disclosed that include preparing and utilizing a mixture of at least one Morus extract enriched for one or more prenylated flavonoids, at least one Scutellaria extract enriched for one or more free-B-ring flavonoids, and at least one Acacia extract enriched for one or more flavans.

Reduced bone density, which often evolves into osteoporosis in aging populations, especially pre- and post-menopausal women, is an important health concern. Osteoporosis is defined clinically through the measurement of bone mineral density (BMD), which remains the best predictor of primary osteoporotic fractures (Kanis et al., Osteoporos. Int. 16:581, 2005). Systemic inflammation is frequently associated with accelerated bone reabsorption, which leads to bone loss. Various mechanisms, such as elevated PGE2, TNF-α, IL-1β and other pro-inflammatory cytokines, have been proposed to be involved with bone loss under inflammatory conditions (Hardy and Cooper, J. Endocrinol. 201:309, 2009).
It has been shown that NSAIDs inhibit the COX enzyme and decrease production of prostaglandins, which are involved in the regulation of bone turnover (Raisz et al., Osteoporos. Int. 3(Suppl 1):136, 1993). The use of cyclooxygenase-2 (COX-2) inhibitors has been demonstrated not only to impair load-induced bone formation, but also to prevent menopause-associated BMD loss (Richards et al., Osteoporos. Int. 17:1410, 2006). For example, diclofenac is an NSAID that inhibits both COX-1 and COX-2 enzymes (Richards et al., 2006). In a human clinical trial, diclofenac was almost as effective as conjugated estrogens for protection of bone loss in postmenopausal women (Bruce et al., Am. J. Med. 96:349, 1994). Cottrell et al. (Bone Joint Res. 2:41, 2013), have reported that a 5-lipoxygenase (LOX) inhibitor can enhance bone regeneration in an animal model. In human clinical trials in postmenopausal women, regular use of the combination of a COX-2 selective NSAID and aspirin has been shown to result in higher BMD at all skeletal sites, including whole body and total hip, as measured by bone density scanning (DXA) and both trabecular and cortical BMD of the lumbar spine by quantitative computer tomography (QCT) (Carbone et al., J. Bone Miner. Res. 18:1795, 2003).
Osteoarthritis (OA), characterized by progressive degeneration of articular cartilage, osteophyte formation, and subsequent joint space narrowing, is the most common form of arthritis that affects an estimated 30.8 million adult population in the US (Cisternas et al., 2016). Despite recent advances in drug discovery, present-day OA management is inadequate due to the lack of primary therapies proven to be effective in modifying disease progression. The current approach focuses mainly on curtailing the sensitivity of disease associated pain (like use of over the counter Non-steroidal anti-inflammatory drugs, NSAIDs), which will only mask the actual etiology leading to irreversible damage to the articular structure. In addition, chronic usages of NSAIDs for symptomatic relief of OA are also limited due to their gastrointestinal, renal and cardiovascular side effects (Bozimowski et al., 2015). As a result, there always is the need for a safe and efficacious natural alternative.
OA is a multifactorial disease with unspecified initial etiology involving articular cartilage, subchondral bone and synovial membrane. Cartilage is the main component of articular structure, and consists of chondrocytes that are embedded in a dense and highly organized extracellular matrix (ECM). ECM is synthesized by the chondrocytes, and is composed of a collagenous network that primarily contains type II collagen, along with glycosaminoglycans (GAGs) and associated proteoglycans. Pro-inflammatory cytokines such as tumor necrosis factor (TNF)-α and interleukin (IL)-1 are known to play important roles in cartilage matrix degradation in the articular cartilage through a cascade of events that lead to stimulation of aggrecanase and matrix metalloproteinase production (Kobayashi et al., 2005). Articular cartilage degradation could also occur as a result of an imbalance in the homeostasis of these fundamental matrix components such as GAGs and type II collagen (Bijlsma et al., 2011). This pathogenesis is triggered in part by the action of inflammatory cytokines, primarily IL-1 (Kapoor et al., 2011; Sandell et al., 2008) that also mediate the production of proinflammatory mediators (including NO and PGE2) and matrix degrading enzymes—aggrecanase and matrix metalloproteinase (MMP). While the catabolic enzymes, MMPs disrupt collagen fibers (Hollander et al., 1994), members of a disintegrin and metalloprotease with thrombospondin (ADAMTS) family degrade aggrecan and both cases result in the release of GAGs (Bondeson et al., 2008). Therefore, plant extracts with proven anti-inflammatory and/or anti-protease/aggrecanase activity could potentially be co-administered with other materials for their potential cartilage protection activity in OA patients.
It is believed that at various stages of OA, all three major structures of the joint (cartilage, subchondral bone and synovium) could be involved in the pathophysiology of the disease which complicates the identification of a single biomarker that is crucial for immediate therapeutic intervention at the early stage of the disease. Nevertheless, among all the major joint biomarkers proposed, C-terminal telopeptide of type II collagen (CTX-II) has been by far the most studied and frequently referred biomarker of cartilage degradation that could be used for the purpose of diagnosis, determining severity of disease or extent of disease progression, prognosis and monitoring efficacy of treatment. It is primarily generated by matrix metalloproteinase activity during cartilage degradation in OA. It is known to show a close link with progression of articular cartilage degradation in OA patients. It's correlation of increased serum, urine or synovial fluid level and articular cartilage degradation were reported both in pre-clinicl and clinical studies (Oestergaard et al., 2006; Garnero et al., 2001). However, there is very limited reports suggesting that plant extracts with inherent characteristic of reducing CTX-II level to be also potentially administered for their cartilage protection activity.
One of the challenges for measurement of clinical efficacy of active agent for prevention and treatment of arthritis and for protection of joint and cartilage integrate heavily relies on subjective WOMAC questionnaires for symptom relieve and x-ray and other diagnostic instrument to measure joint space area and joint space narrowing, which requires significant number of subjects and many months long treatment. It is clinically relevant for finding novel natural compositions that can demonstrate modulation of objective clinical measurements such as CTX-II biomarkers associated with joint health.
Recently, we reported a botanical composition designated as UP1306 (a proprietary blend of two bioflavonoid standardized extracts from the heartwood of Acacia catechu and root bark of Morus alba) with analgesic and anti-inflammatory effects which was discovered through the in vivo screening of known traditional folk-medicines suggesting its usage for OA associated symptoms relief (Yimam, et al., 2016). UP1306, administered orally at a dose of 300 mg/kg, resulted in 46.3%-53.3% reductions in paw edema and 43.6%-54.8% reductions in pain sensitivity in the carrageenan induced rat paw edema model as well as a 34.4% reduction in visceral pain sensitivity in the Writhing's model in mice (Yimam et al., 2016). In vitro, it showed dose-dependent inhibition of the enzymatic activities of COX and LOX with IC50 values of 20.9 μg/mL, 49.2 μg/mL, and 11.1 μg/mL in COX-1, COX-2, and 5-LOX, respectively (Yimam et al., 2016).
Previously we have also documented that, a bioflavonoid composition—UP446, which comprises baicalin from Scutellaria baicalensis and catechin from Acacia catechu to possess bioactivities including: (i) dual inhibition of COX and LOX (Burnett et al., 2007) (ii) normalization of COX-2, TNF-α, IL-1β, IL-6, and NF-κB gene expression in lipopolysaccharide (LPS)-induced human and animal cell lines (Tseng-Crank et al., 2010) (iii) inhibition of COX-2, 5-LOX, and inducible-nitric oxide synthase (iNOS) gene expression and moderation of NF-κB binding activity in endotoxin-stimulated rat peritoneal macrophages (Altavilla et al., 20090). Beneficial applications in OA related symptomatic pain relief has also been reported for UP446 from human clinical trials (Sampalis and Brownell, 2012; Arjmandi et al., 2014).
There is no report of using these compositions alone or in combination to reduce CTX-II biomarkers associated with joint health, bone health, or a combination thereof.

Compositions and methods for managing or improving bone disorders, joint disorders, cartilage disorders, or a combination thereof


A pet grooming comb includes a grip having a plurality of first coupling portions circularly arranged around a longitudinal axis thereof and a comb head having a plurality of teeth and a second coupling portion selectively coupled to one of the first coupling portions. Thus, a user can adjust a setting angle of the comb head relative to the grip by means of the engagement of one of the first coupling portions of the grip with the second coupling portion of the comb head, thereby enhancing convenience of use.

1. Field of the Invention
The present invention relates generally to pet supplies, and more specifically to a pet grooming comb that can allow adjustment of the combing angle conveniently.
2. Description of the Related Art
A conventional pet grooming comb generally includes a grip, a comb head fixed to the grip, and a plurality of teeth fixed to the comb head such that a user can hold the grip to force the teeth to comb a pet's hair.
Since the comb head is fixed to the grip and unrotatable, the teeth that are fixed to the comb head face a fixed direction. However, a pet has different characteristics of hair at different positions, and therefore a user needs to adjust a holding angle of the pet grooming comb or change a way of holding the grip to enable the teeth to approach the pet's skin for combing the pet's hair. Thus, it can be seen that the conventional pet grooming comb has the drawback of requiring strenuous efforts to operate, resulting in inconvenience of use.

This patent is subject to a terminal disclaimer.

Pet grooming comb capable of adjusting combing angle


A cubic spline interpolation (CSI) method and apparatus for image compression by direct computation. Such a CSI method is used along with the JPEG standard to obtain a new CSI-JPEG encoder-decoder (Codec). In one embodiment, the present invention is a method and apparatus for a new CSI-JPEG codec enabling a pipelined compression method that is naturally suitable for hardware or firmware implementations.

In T. K. Truong, L. J. Wang, I. S. Reed, and W. S. Hsieh, "Image data compression using cubic convolution spline interpolation," IEEE Trans. on Image Processing, vol. 9, no. 11, pp. 1988–1995, November 2000 [1]; and L. J. Wang, W. S. Hsieh, T. K. Truong, I. S. Reed, and T. C. Cheng, "A fast efficient computation of cubic-spline interpolation in image codec," IEEE Trans. on Signal Processing, vol. 49, no. 6, pp. 1189–1197, June 2001 [2], the entire contents of which are hereby expressly incorporated by reference, a cubic spline interpolation (CSI) is developed in order to subsample image data to achieve compression. The CSI scheme is combined with the JPEG algorithm to develop a modified JPEG encoder-decoder, which obtains a higher compression ratio and a better quality of reconstructed image than the standard JPEG In the CSI algorithm developed in [1], a fast Fourier transform (FFT) algorithm used in the modified JPEG encoder, is applied to perform the circular convolution needed to compress and reconstruct image data.
Recently, the authors in [2] showed that if the size of compressed image is not chosen to be power of two, the usual 2-D FFT is not the best algorithm needed to obtain the compressed image values. To overcome this problem, the authors proposed the Winograd discrete Fourier transform (WDFT) with the overlap-save method instead of the FFT to implement the CSI scheme. The disadvantage of this faster CSI algorithm is the overlap-save method with its required boundary conditions. Thus this algorithm though faster is not readily realized as a real-time processor.
Therefore, there is a need for a method and apparatus for a faster and more efficient computation of a CSI for image signals.

System and method for a direct computation of cubic spline interpolation for real-time image codec


A comparator includes a first inverter which is inserted between a power source terminal and one end of a first variable resistor, includes a first FinFET provided with a first gate terminal for receiving a positive phase output signal, and a second gate terminal for receiving a clock signal changing between a first level and a second level, inverts the positive phase output signal, and outputs a negative phase output signal, and a second inverter which is inserted between the power source terminal and one end of a second variable resistor, includes a second FinFET provided with a third gate terminal for receiving the negative phase output signal, a fourth gate terminal for receiving the clock signal, and the same polarity as the first FinFET, inverts the negative phase output signal, and outputs the positive phase output signal.

1. Field of the Invention
The present invention relates to a comparator for comparing an input signal with a reference signal, and an analog-to-digital converter using the comparator.
2. Description of the Related Art
In general, a comparator (analog comparator) is configured to compare an analog input voltage with a reference voltage, and output a digital signal of a high (H) level or a low (L) level according to a comparison result. Further, in the analog-to-digital converter (hereinafter simply referred to as an ADC), a plurality of comparators having different reference voltages are used to convert an analog input voltage into a digital signal. In an ordinary ADC, a voltage generating circuit for generating a plurality of different reference voltages becomes necessary.
As a method of configuring a comparator, a comparator including a circuit in which input sections and output sections of two inverters are connected to each other in an annular form is known. According to "Thomas Bynghak Cho, and Paul R. Gray, "Thomas Byunghak Cho, and Paul R. Gray, "A 10 b, 20 Msample/s 35 mW Pipeline A/D Converter", IEEE J. of Solid-State Circuits Vol. 30, No. 3, March 1995. (FIG. 1)" (related art), as one of comparators having the annular circuit, a comparator of a built-in threshold type is described.
In the built-in threshold type comparator, a variable resistor a resistance value of which changes according to the input voltage and the reference voltage is provided between each of both the inverters and the power source (high potential power source) or between each of both the inverters and the ground power source (low potential power source). Each of both the inverters is provided with two switches (transistor switches) which are called a reset switch, and an on/off switch. The reset switch is used to reset an output voltage of the inverter to the power source voltage or the ground power source voltage. The on/off switch is inserted in series between an NMOS transistor and a PMOS transistor of the inverter, and is used to control turning on/off of the inverter by closing or opening the connection between the two transistors. A description will be given below on the assumption that the variable resistor is provided between each of both the inverters and the ground power source, and the reset switch is used to reset the output voltage of the inverter to the power source voltage.
In the built-in threshold type comparator, the output is reset before the comparison operation is started. That is, the reset switches of both the inverters are set ON, and the outputs of both the inverters coincide with the power source voltage. As a result of this, it is possible to prevent an influence of the previous comparison result from propagating to the next comparison result. Further, during the period in which the reset switch is in the on-state, the on/off switch is set in the off-state, and thus the shoot-through current is suppressed, thereby reducing the power consumption.
After the above-mentioned resetting is completed, the comparison operation is performed. At the time of the comparison operation, the reset switch is set in the off-state, and the on/off switch is set in the on-state. Then, a current flows from an output terminal of each of both the inverters to the variable resistor, and a voltage drop is caused. At this time, the resistance values of both the variable resistors differ from each other depending on the values of the input voltage and the reference voltage, and hence the voltage falling speeds of both the inverter outputs differ from each other. As a result of this, a latch state where the one inverter output is high, and the other inverter output is low is obtained.
In the ADC using such a built-in threshold type comparator, the reference voltage can be scaled up/down by changing the size ratio of the transistor for receiving the input voltage to the transistor for receiving the reference voltage. Accordingly, the number of reference voltages to be generated may be one, and a voltage generating circuit for generating a plurality of reference voltages is not necessary unlike the ordinary ADC.
In the built-in threshold type comparator described in the related art, the operation speed is lowered by the ON resistance of the on/off switch. If the size of the transistor used for the on/off switch is made larger, the ON resistance can be made small. In this case, however, a capacitance of the parasitic capacitor is increased concomitantly with an increase in size. If the parasitic capacity is increased, the operation speed of the comparator is lowered, and hence increasing the transistor size of the on/off switch is not always connected with improvement in the operation speed.

Comparator and analog-to-digital converter using the same


Provided is a flexible display apparatus. A shape deformation sensor is formed in at least one of a first plurality of connection lines of a flexible display panel and a second plurality of connection lines of a touch screen panel. The shape deformation sensor is configured to sense a shape deformation of the flexible display panel.

1. Field
One or more exemplary embodiments relate to a flexible display apparatus.
2. Description of the Related Art
In recent years, with the advent of an information-oriented society, display apparatuses configured to process a large amount of information and display the information have progressed quickly. Thus, various display apparatuses have been developed and highlighted.
A liquid crystal display (LCD) device, a plasma display panel (PDP) device, a field emission display (FED) device, and an electroluminescence display (ELD) device have been developed as display apparatuses. These display apparatuses are gradually being made to be relatively thin and lightweight and to consume low power. However, since the above-mentioned display apparatuses use a glass substrate to resist high heat generated during a fabrication process, there may be a technical limit to making the display apparatuses thin and lightweight or flexible.
Accordingly, much attention has recently been paid to development of a flexible display apparatus capable of retaining display performance even if the flexible display apparatus is bent like paper, by using a flexible material (e.g., a plastic film) which is capable of being folded and unfolded, instead of an inflexible glass substrate. The flexible display apparatus may be thin and lightweight, highly resistant to impact, and carried while being folded or rolled because the flexible display apparatus may be warped or bent. Further, the flexible display apparatus may be manufactured in any of various shapes and thus, widely applicable in the future.
The above-described flexible display apparatus may adopt a sensor configured to sense a shape deformation in order to measure an extent to which the flexible display apparatus is folded or bent and a direction in which the flexible display apparatus is folded or bent. As an example of a sensor configured to sense a deformation of a shape of the flexible display apparatus, a transparent electrode material applicable to touch screens or a hall sensor may be used.
A structure using the transparent electrode material may include a plurality of horizontal electrodes and a plurality of vertical electrodes that are arranged to intersect one another. The structure using the transparent electrode material may be utilized in a variety of ways, not only in display devices but also in the field of touch screens. In a shape deformation sensing technique using the transparent electrode material, since an additional ITO film is adhered to a top surface or bottom surface of a flexible display panel, a thickness of the flexible display apparatus may be bound to increase. When the thickness of the flexible display apparatus increases, a radius of curvature that may be allowed during a folding or bending operation may be limited. In particular, as the thickness of the flexible display apparatus increases, a displacement of an inner surface or outer surface may increase during the folding or bending operation, and the flexible display apparatus may be more likely be damaged. Further, since an indium tin oxide (ITO) film applied to a typical touch screen may detect a state of contact or non-contact with respect to a specific point, the ITO film may be technically limited when it comes to detecting simultaneous deformation (i.e., folding or bending operations) of several points or detecting a bending extent and direction.
In a structure using a hall sensor configured to sense a magnetic field, a plurality of hall sensors may be arranged in a widthwise or lengthwise direction of a flexible display apparatus, and a variation in the position of a magnetic body disposed at a specific point may be detected in order to sense a deformation of the flexible display apparatus. However, a shape deformation sensing structure using a hall sensor may be limited in that deformation may be sensed under specific conditions, for example, in that a deformation of the flexible display apparatus (e.g., carrying the flexible display apparatus while being rolled or folded) may be sensed only when the deformation occurs only in a direction in which hall sensors are arranged. Furthermore, it may be difficult for the structure using the hall sensor to sense a folding or bending extent and direction.


The invention relates to a finder pattern for detection and location of at least one target feature in a target object. The finder pattern includes at least two triads arranged in predetermined locations in the target object, wherein each triad includes a first blob, a second blob, and a third blob, wherein each blob has substantially the same area and is positioned in a predetermined location in the target object. The locations of the first and second blobs are substantially equidistant from the third blob, and the locations of the first, second, and third blobs are not collinear. The invention further relates to a method for detecting a finder pattern in a target object, and a computer readable medium having instructions stored therein for detecting a finder pattern in a target object, which, when executed by a processor of a computing device, cause the computing device to carry out the steps of the method.

Conveniently it is known to use finder patterns to find and identify a wide variety of information on articles and products. Finder patterns are present in most machine readable media, such as common barcodes and two dimensional machine readable codes.
Printed one dimensional barcodes like UPC and Code 39 are well known in the art. They read by electronic sensors scanning along a single line through a printed set of parallel lines of varying width which constitute the code. The information sensed by scanning is passed through logic circuitry which senses the position of codes by detecting starting and stopping positions of code elements along the scan lines and senses timing information to recover size metrics of the code. The characteristics of a code that reveal its position and metrics are commonly referred to as its "finder pattern". Data content of any codes can only be recovered after the position and metrics of the code are known. In the case of one dimensional codes, the finder pattern design is extremely simple, but typically accounts for 10% or more of the total space occupied by a code. Additionally, one dimensional barcodes are very limited in the amount of data they can carry, and have poor data density.
Many two dimensional codes have been invented to meet the need for larger amounts of data and better data density. Such codes are commonly designed to carry data in a regular rectangular array of elements, much like the older human and mechanical codes like Braille, the player piano scroll, and the punch card. To read such codes with electronic sensing devices requires more sophisticated finder pattern designs that the simple types found in one dimensional codes. Various 2D machine readable code formats like Dot Code A (Phillips Dot Code), PDF-417, Data Matrix, Snowflake and QR-Code are examples of 2D machine readable codes. All of these have specific pattern components to help identify the presence, position, and metrics of the data elements of the code.
As part of their evolution from one dimensional codes, many two dimensional codes have finder patterns that anticipate looking for high contrast line edges with a known sequential spacing pattern detected by scanning along a single scan line (e.g.—PDF-417 and QR). They work well in an environment where the target object is at a known orientation relative to the sensor, and where lighting is well controlled. They are most effective when there is no perspective distortion. Perspective distortion is well known and mathematically understood. In the case of two dimensional surfaces, it occurs when the target surface plane is not perfectly perpendicular to the optical axis or line of sight from the sensor. Such distortion causes a number of problems for processing logic used to identify and locate the finder patterns. For example, points that are equidistant on a target are not typically equidistant in an image under perspective distortion. Also, lines that are parallel on a target will generally not appear to be parallel in an image under perspective distortion. Accordingly, additional algorithmic complexity is required to compensate for the perspective distortions. Although the mathematics of perspective has been well understood for centuries, finder patterns for barcodes have not been designed to easily facilitate correction for this distortion.
U.S. Pat. No. 6,267,296 illustrates a QR finder pattern. The QR finder pattern is an example of a conventional finder pattern, which performs poorly when perspective distortion is present. This pattern is found by recognizing the successive length ratios of light and dark elements along a scan line through large nested-squares patterns in each of three primary corners of a QR code. The method is effective to locate the code when the code is oriented in an un-rotated position and/or the plane of the target is perpendicular to the optical axis of the camera. However, if the QR target is rotated, so that laser scan lines are not perfectly aligned with the rectangular edges of the code, (or equivalently, so that a line of image pixels in a digital camera is not perfectly aligned with the rectangular edges of the code in that image), or if the plane of the target is tilted with respect to the optical axis, then the effectiveness of the finder method substantially decreases. Wide tolerances and/or additional scan line searches must be performed to reliably find the code in different orientations. This added complexity and process steps are disadvantageous.
Most conventional finder patterns are effective under good focus conditions, but rapidly degrade in the presence of blur. For example, U.S. Pat. No. 5,053,609 discloses a Data Matrix code finder pattern. The primary finder pattern of this code includes solid straight line edges on two bounding sides of the code. The edge lines, under good focus conditions, may be detected by identifying points of high gradient value on a series of parallel pixel scan lines through an image. After locating these high-gradient feature points, it is necessary to find two significant subsets of these points that fall predominantly in straight lines. The lines formed by these two subsets are interpreted to be the outer edges of two sides of the full Data Matrix code.
Under blur conditions, high image gradients are strongly attenuated and may appear to be displaced, depending on nearby elements. Blur can be modeled as an optical "circle of confusion" which spreads the light which should ideally be focused on a single point in the image over the entire area of the circle. In this way, light or dark neighboring elements with the circle of confusion can contribute to the observed gradient at the center of the circle. Thus, what might be a point of highest gradient (an "edge") in a perfectly focused image may not be the point of highest gradient in a blurred image. Specifically, when the diameter of the circle of confusion equals or exceeds the width of the solid line sides of the Data Matrix code, therefore, the location of the feature points can strongly distorted in a way that is dependent on the brightness of nearby points, especially the varying data elements inside the code. The estimated feature point locations may be significantly distorted and may not appear to be colinear. Other common issues like sensor noise, shadows, and lighting gradients, also affect the feature point location estimates. As a result, feature points may appear to lie on a series of broken line segments with varying orientations, rather than the long straight lines that are the edges of the real-world target. Thus, the long edges may not be recognized, or they may not be recognized for their full length and significant error can be introduced into the estimated location and orientation. Long straight line finder patterns which are common in one dimensional codes do not work very well generally with 2D codes.
Finder patterns for 2D codes almost always include a timing pattern. These secondary parts of the finder pattern assist, e.g., in calibrating the number of data elements and the local unit distance for their spacing in an image of the target. A common conventional timing pattern includes a known pattern of alternating contrast elements along one or more lines at specific positions in the target. Such timing patterns are found in QR, Data Matrix, and Snowflake code.
U.S. Pat. No. 5,825,015 illustrates a Snowflake code pattern. The timing pattern includes a fixed pattern of all dots all along one of the two matrix array diagonals. The pattern is used to determine the size of the Snowflake code and is a primary target of a search strategy to find the code. The diagonal, however, uses a large number of dots otherwise available to convey data, and introduces a visually distinct pattern in what would otherwise be a bland field of dots for a human observer. Additional elements of the Snowflake finder pattern include special two-tiered information carrying structures in each corner of the code. In total, the finder pattern for a Snowflake code occupies about a quarter of the total target object area of the code.
QR code also utilizes vertical and horizontal timing patterns between its corner squares. In the more common smaller capacity QR codes, the finder pattern and other fixed elements of the code may occupy nearly half of the target object code area.
Data Matrix code also utilizes timing patterns. These timing patterns constitute the two remaining sides of the code. They consist of an alternating series of small dark and light elements along the borders of the Data Matrix square opposite from the solid straight lines used as an initial finder pattern. (For large code sizes, Data Matrix also introduces additional solid line patterns and timing patterns on the interior of the code.) After an initial estimate of the position of a Data Matrix code is determined by locating the two solid line edges of the code as described before, it is necessary to locate the location and orientation of both timing pattern lines accurately. This is required because the perspective distortion cannot be determined from knowledge of the location and orientation of only two lines. Four lines (or four points) are required. Determining the location and orientation of lines of alternating light and dark modules, especially under blur and shadow conditions, requires a time consuming computational process that typically has poor error characteristics. Data Matrix thus has a poorly designed finder pattern for use in conditions where perspective, blur, and other distortions are likely. Moreover, the timing patterns require a substantial percentage of the available space, thereby limiting the overall data density of the code.
As shown for the foregoing, finder patterns known in the art have a number of disadvantages. They cope poorly with common problems like perspective and blur, and they typically occupy a significant percentage of the target object code area.
In addition, conventional finder patterns, such as the QR, Data Matrix, and Snowflake patterns, are typically visually distinctive graphical elements. Accordingly, the finder patterns are aesthetically objectionable to graphic artists because they tend to clash with product artwork and/or detract from the overall appearance of product packaging. These finder patterns make it difficult to introduce consumer friendly branding or colorful graphic information, e.g., icons, calling attention to intended use or data content. The visual dominance of finder patterns can detract from and limit the effectiveness of iconic information elsewhere on the target. Clearly, they are not appropriate for other related applications such as assisting in machine recognition of symbols, logos, artwork, and general objects in the real-world.
Artistic graphic packaging elements can cause significant technical problems for a decoder by introducing structures that will confuse finder algorithms. For example an icon with a rectangular border near a Data Matrix code or QR code can introduce edges which may be confused with the correct edges of the code. Accordingly, graphics must usually be placed at a considerable distance from all other elements of the code for the finder and data decoding algorithms to work properly.
Moreover, most existing finder patterns form part, or all, of the overall geometric outline of the two-dimensional (2D) code with which they are associated. Accordingly, the finder patterns must typically occur in specific locations, e.g., outside or protruding from the outside, or at the corners of the code, thereby, introducing limitations in the overall shape of codes and in the range of code sizes that are available or practical.
In additional, the conventional finder patterns typically do not work well on non-linear geometries, e.g., a curved enclosure outline or an outline with concave portions. Such flexibility in the overall shape of the machine readable portion of is desirable to create consumer recognizable and consumer friendly codes.

Efficient finder patterns and methods for application to 2D machine vision problems


A light-shielding film 2 is formed on a transparent substrate 1. A hard mask film 3 is formed on this light-shielding film 2. The entire hard mask film 3 is made of a chromium-containing material including tin. The film made a chromium-containing material including tin can cause a significant increase in the etching rate at the time of chlorine-containing dry etching. Furthermore, comparing with a film made of a chromium-containing material in which part of chromium is replaced with a light element, the above film has an equal or higher level of etching resistance to fluorine-dry etching. Thus, burden on a photoresist at the time of etching the chromium-containing material film can be reduced. Therefore, high-precision pattern transfer can be performed even in the case that the resist film is thinned.

In the field of semiconductor technology, research and development for further refinement of patterns have been progressed. In recent years, particularly, with high integration of a large scale integration circuit, refinement of circuit patterns, wiring patterns, or contact-hole patterns for wiring between layers forming a cell has been progressed, and a request for microfabrication technology has been increased.
In connection with this, even in the field of technology for photomask production to be used in the process for photolithography in microfabrication, a technique for forming fine and correct circuit patterns (mask patterns) has begun to be demanded.
Generally, reduction projection is performed when forming a pattern on a semiconductor substrate by photolithographic technique. The size of the pattern formed on the photomask is therefore approximately four times larger than the side of the pattern formed on the semiconductor substrate. However, this does not mean that the desired precision of the pattern formed on the photomask is smaller than the pattern formed on the semiconductor substrate. Rather, the precision of a pattern formed on the photomask as a master is desired to be higher more than an actual pattern obtained after exposure.
In today's photolithography technical field, the size of a circuit pattern to be drawn is considerably smaller than the wavelength of light to be used for exposure. Thus, in the case of forming a photomask pattern with a just four-times larger circuit pattern, light interference or the like, which is generated under exposure, influences on transfer of an original shape. As a result, the original shape cannot be transferred onto the resist film of a semiconductor substrate.
In some cases, therefore, a pattern formed on the photomask is made more complicated than an actual circuit pattern to reduce an effect of the above light interference or the like. The shape of such a pattern may be, for example, an actual circuit pattern subjected to optical proximity correction (OPC).
Hence, along with a decrease in size of a circuit pattern, a higher precision processing technique has been also desired in a lithographic technique for forming photomask patterns. Although lithography performance may be expressed in limiting resolution, as described above, the precision of a pattern formed on the photomask as a master is desired to be higher more than an actual pattern obtained after exposure. Thus, limiting resolution required for formation of a photomask pattern is almost equal to or higher than one required in lithography for forming a pattern on a semiconductor base.
In general, when forming a photomask pattern, a resist film is formed on the surface of the photomask blank in which a light-shielding film is mounted on a transparent substrate, and a pattern is then drawn (exposed) on the resist film by an electron beam. Subsequently, after obtaining a resist pattern after developing the exposed resist film, the light-shielding film is etched by using this resist pattern as a mask to obtain a light-shielding (film) pattern. The light-shielding (film) pattern thus obtained is served as a photomask pattern.
In this case, the above resist film should be thinned depending on the degree of fineness of the light-shielding pattern. This is because, when forming a fine light-shielding pattern while keeping the thickness of the resist film, the ratio (aspect ratio) of the thickness of the resist film to the size of the light-shielding pattern becomes large and causes troubles of failed pattern transfer, falling down or peeling off of the resist pattern, or the like due to deterioration of the shape of the resist pattern.
On the other hand, in the conventional photomask blank, when patterning is performed by making the resist film thinner, damage received by the resist in etching process may cause deterioration or regression of the pattern shape. In this case, a resist pattern cannot be correctly transferred to a light-shielding film, and a photomask with high patterning precision cannot be made. Thus, various investigations have been performed with respect to a photomask blank having a structure that enables high-precision patterning even if a resist film is made thinner.
For example, in JP 2006-78807 A (Patent Document 1), there is disclosed a light-shielding film having a structure in which at least one layer is made of a material mainly containing silicon and a transition metal and having an atomic ratio of silicon and metal of 4 to 15:1 (silicon: metal). The layer made of a material containing silicon and a transition metal can be processed by fluorine-containing dry etching. The fluorine-containing dry etching has a low level of damage to a resist pattern. Thus, employing the above structure may lead to a light-shielding film for ArF exposure having excellent light-shielding ability and processability.
In JP 2007-241060 A (Patent Literature 2), there is disclosed a method for further enhancing processability of a light-shielding film containing silicon and a transition metal by using a hard mask as a thin film made of a chromium-containing material.
Conventionally, as an optical film such as a light-shielding film and a half-tone phase shift film, a transition-metal compound film and a silicon compound film have been used. Here, the transition-metal compound film includes a transition metal and a light element such as oxygen, nitrogen, or carbon, which can be selected as appropriate. Especially, a chromium-containing material film and a molybdenum silicon-containing material film have been widely used as an optical film.
In the case that a light-shielding film is a film made of a chromium-containing material, if a resist film for patterning this light-shielding film is made thin, it becomes difficult to fully secure the etching resistance of the light-shielding film in patterning process. In Patent Literature 2, therefore, to make fine pattern processing possible even when a resist film is made thin, a photomask blank is proposed so that a light-shielding film is a film made of a material processable with fluorine-containing dry etching.
Using a thin chromium compound film as a hard mask film is also disclosed by this Patent Literature 2 in order to perform precise patterning to the light-shielding film which comprises a transition metal silicon compound. Using a thin chromium compound film as a hard mask film is also disclosed. Although the hard mask film made of such a chromium compound is patterned by transferring a resist pattern, it is supposed that the precision of such patterning can be secured by sufficiently reducing the thickness of the hard mask film.

Photomask blank and method for manufacturing photomask


The invention provides a hinge connector for a folding-type electronic apparatus including a first housing, a second housing, a first electronic unit disposed in the first housing, and a second electronic unit disposed in the second housing. The hinge connector, according to the invention, includes a first shaft member, a second shaft member, a frame member and a flexible conductive element. By the hinge connector according to the invention, the second housing is capable of rotating around two axes relative to the first housing, and the first electronic unit electrically connects with the second electronic unit. In particular, during the operation of the electronic apparatus, the portion of the flexible conductive element within the first shaft member and the second shaft member is twisted rather than bent.

1. Field of the Invention
The present invention relates to a hinge connector used in a folding-type electronic apparatus for assisting in connecting a folder module of the electronic apparatus to a main module of the electronic apparatus. Moreover, the folder module is rotatable around two axes relative to the main module. A first electronic unit of the main module is electronically connected with a second electronic unit of the folder module. The related prior arts are listed as follows:    [1] U.S. Pat. No. 6,616,467;    [2] U.S. Pat. No. 5,394,297;    [3] U.S. Pat. No. 5,141,446; and    [4] The mobile phone of Samsung with the model number of SGH-P408.
2. Description of the Prior Art
The folding-type electronic apparatus is often utilized in designs of electronic consumer products, e.g. mobile phone, personal digital assistant (PDA), digital camera (DC), notebook, and so on. The typical folding-type electronic apparatus comprises a main module and a folder module. The main module consists of a first housing and a first electronic unit disposed in the first housing. The folder module consists of a second housing and a second electronic unit disposed in the second housing.
The so-called folding-type electronic apparatus is that the folder module thereof utilizes a hinge connector to connect the second housing and the first housing, such that the second housing is rotatable around an axis or two axes relative to the first housing. When the second housing rotates around an axis relative to the first housing, the hinge connector can rotate in one degree of freedom. When the second housing rotates around two axes relative to the first housing, the hinge connector can rotate in two degrees of freedom. Moreover, the second electronic unit of the second housing is electronically connected to the first electronic unit of the first housing by arranging the hinge connector with a flexible conductive element, e.g. a flexible printed circuit board (FPCB) or a coaxial cable.
However, for the hinge connector capable of rotating in one degree of freedom, the flexible conductive element will be exposed to destructive bending stress while the folding-type electronic apparatus is folded, resulting in broken circuit or short circuit in the tiny circuit of the flexible conductive element. For the hinge connector capable of rotating in two degrees of freedom, the flexible conductive element will be exposed to even more destructive bending stress while the folding-type electronic apparatus is folded. For the flexible conductive element of the hinge connector capable of rotating in one degree of freedom, although the prior arts have proposed some special designs for reducing the bending stress of the flexible conductive element or for reducing the occurrence of broken circuit or short circuit while the tiny circuit of the flexible conductive element is being exposed to the bending stress, the above prior arts not only cannot be applied to the hinge connector capable of rotating in two degrees of freedom but also cost a lot.
Furthermore, the assembly of the general hinge connector capable of rotating in two degrees of freedom is always complex, so that the manufacturing cost of the folding-type electronic apparatus is raised.
Therefore, an objective of the present invention is to provide a hinge connector for a folding-type electronic apparatus, wherein the hinge connector can rotate in two degrees of freedom. Especially, according to the hinge connector of the present invention, the flexible conductive element receives a twisting stress instead of a destructive bending stress while the electronic apparatus is being folded.
Another objective of the present invention is to provide a hinge connector for a folding-type electronic apparatus, wherein the hinge connector can rotate in two degrees of freedom and can be assembled easily.

Hinge connector for folding-type electronic apparatus


In a sheet conveying device, a multi-function frame in which optional devices such as a stack bypass, an envelope supplying unit and the like are mountable is connected to on an upstream of a conveyance frame defining a bottom surface of a sheet conveyance passage. A registration guide is pivotably supported on a downstream end portion of the multi-function frame and selectively shiftable over a first position of defining an upper surface of the sheet conveyance passage and a second position of opening an upper portion of the sheet conveyance passage. As a result, a sheet jam processing in the vicinity of the registration roller can be easily conducted.

1. Field of the Invention
The present invention relates to a sheet conveying device for conveying a sheet to an image forming section, and an image forming apparatus provided with the same, such as a digital copying machine, laser printer and the like. Particularly, it relates to a sheet jam processing function at the time of sheet conveyance.
2. Description of the Related Art
A conventional image forming apparatus is provided with an image forming section at a center thereof. In the image forming section, a predetermined image is formed by respective steps of charging, exposing, developing, and transferring. In order to form a fine image by using the image forming section, it is necessary to control the timing at which a sheet is conveyed to the image forming section and to correct an oblique conveyance of the sheet. For this reason, the conventional image forming apparatus is provided with a sheet conveying device including a registration roller and peripheral members thereof as disclosed in Japanese Unexamined Patent Publication No. Hei. 5-58500.
FIG. 9 is a cross sectional view showing a periphery of the sheet conveying device provided in the conventional image forming apparatus. In FIG. 9, a photoconductive drum (not shown) is accommodated inside a drum unit 20. A transferring roller 16 is provided beneath the drum unit 20. The photoconductive drum and the transferring roller 16 are used to transfer a toner image onto a sheet conveyed by a pair of registration rollers 14. A pair of conveying rollers 13 for conveying the sheet conveyed from a sheet supplying cassette or a stuck bypass (not shown) to the pair of registration rollers 14 are provided on an upstream of the pair of registration rollers 14 in the sheet conveyance direction.
In a state that the registration rollers 14 are suspended, a leading end of the sheet conveyed through the pair of conveying rollers 13 and the sheet conveyance passage 22 comes into contact with a nip portion of the pair of registration rollers 14 and the oblique conveyance of the sheet is corrected. Thereafter, the pair of registration rollers 14 are driven to convey the sheet in synchronization with the timing of the image formation of the image forming section. A registration guide 23 is provided above the sheet conveyance passage 22 between the pair of registration rollers 14 and the pair of conveying rollers 13.
A detecting sensor 24 detects a presence of the sheet which passes through the sheet conveyance passage 22, and is provided in the vicinity of the registration guide 23 in such a manner that an emitting surface of the detecting sensor faces the sheet conveyance passage 22. The detecting sensor 24 detects a passing of the leading end of the sheet, and the detection is sent to a controlling section (not shown) of a main body of the image forming apparatus. A contact-making amount (slackness amount) of a sheet against the pair of registration rollers 14 is determined by controlling the time period from the passing of the leading end of the sheet to a stopping of the driving of the pair of conveying rollers 13 by the controlling section. Further, the detecting sensor 24 detects a non-standardized sheet by continuously detecting the sheet from the leading end to the tailing end to detect a size of the sheet. The sheet size is used when the controlling section determines a suspension time of the pair of registration rollers 14 and a suspension time of the image formation.
FIG. 10 is a perspective view showing an image forming apparatus in which a developing unit 5 positioned above the sheet conveyance passage 22 is taken off, and a sheet jam processing is conducted from above. FIG. 10 shows the state that the developing unit 5 is taken off, and a part of the main body including the drum unit 20, the registration guide 23, and the like is omitted. An upper portion of the sheet conveyance passage 22 is opened from a stuck bypass 11b to the pair of registration rollers 14 (see FIG. 9.) by taking the developing unit 5 off to conduct the sheet jam processing in the sheet conveyance passage 22.
In the foregoing conventional image forming apparatus, the registration guide 23 (see FIG. 9.) is so designed to be pivotable in upwardly and downwardly about a pivot positioned in the vicinity of the registration rollers 14. Thus, when the sheet jam processing is conducted, the registration guide 23 is rotated toward the side of the drum unit 20 to remove the sheet.
However, a user is required to stretch his/her arm into a narrow space in the vicinity of the pair of the registration rollers 14 to rotate the registration guide 23 to remove the jammed sheet. In addition to that, the space for the pivotal of the registration guide 23 is limited due to the drum unit 20 positioned above the pair of registration rollers 14. Accordingly, it has not been easy to conduct the sheet jam processing. Further, there is not any means for rotating the registration guide 23. Consequently, the operation is troublesome.

Sheet conveying device and image forming apparatus provided with the same


A vehicle-side connector (C) to which a charging connector is to be connected includes a housing (20) capable of accommodating vehicle-side terminal fittings (11) fixed to ends of wires (10) drawn out from a battery in a vehicle. A connector fitting portion (25) is provided in a front part of the housing (20), and the charging connector can fit therein so that terminal connecting portions (13) of the vehicle-side terminal fittings (11) are electrically connectable to the charging connector. A terminal accommodating portion (30) is provided in a rear part of the housing (20) and is capable of accommodating parts of the vehicle-side terminal fittings (11) behind the terminal connecting portions (13), The terminal accommodating portion (30) is formed with a first draw-out opening (32) through which the wires (10) can be drawn backward and a second draw-out opening (33) through which the wires (10) can be drawn out laterally.

1. Field of the Invention
The invention relates to a vehicle-side connector to which a charging connector is to be connected at the time of charging.
2. Description of the Related Art
US Patent Application Publication No. 2011/0287667 discloses a vehicle-side connector that includes a housing capable of accommodating a vehicle-side terminal fitting connected to an end part of a wire drawn out from a battery or the like in a vehicle. The vehicle-side terminal fitting accommodated in the housing is held retained by a retainer mounted in a rear side of the housing. The wire is drawn out to a side behind the vehicle-side connector through a cut hole formed on the retainer.
The layout of parts in an engine component differs depending on vehicle type, and hence a sufficient space may not be ensured immediately behind the vehicle-side connector. In such a case, it is desired to draw out the wire laterally from the vehicle-side connector and reduce a backward projecting distance from the vehicle-side connector as much as possible. However, the backward projecting distance of the vehicle-side connector cannot be reduced sufficiently. Thus, it has been necessary to prepare housings having different shapes for a case where the wire is drawn out backward from the vehicle-side connector and a case where the wire is drawn out laterally from the vehicle-side connector.
The invention was completed based on the above situation and aims to enable the use of a vehicle-side connector regardless of spatial restriction.

Vehicle-side connector having a housing with wire draw-out openings in different directions


In one embodiment, a number of speed control rate candidates are determined for a speed control command of operating an autonomous vehicle. For each of the speed control rate candidates, a number of individual costs are calculated for the speed control rate candidate by applying a plurality of cost functions, each cost function corresponding to one of a plurality of cost categories. A total cost for the speed control rate candidate is determined based on the individual costs produced by the cost functions. One of the speed control rate candidates having a lowest total cost is selected as a target speed control rate. A speed control command is generated based on the selected speed control rate candidate to control a speed of the autonomous vehicle.

Vehicles operating in an autonomous mode (e.g., driverless) can relieve occupants, especially the driver, from some driving-related responsibilities. When operating in an autonomous mode, the vehicle can navigate to various locations using onboard sensors, allowing the vehicle to travel with minimal human interaction or in some cases without any passengers.
Motion planning and control are critical operations in autonomous driving. However, conventional motion planning operations estimate the difficulty of completing a given path mainly from its curvature and speed, without considering the differences in features for different types of vehicles. Same motion planning and control is applied to all types of vehicles, which may not be accurate and smooth under some circumstances.
In addition, speed control is a critical step in autonomous driving. When seeking a speed control accuracy, one usually requires a high speed control (e.g., throttle, brake) changing rate. However, a high changing rate may be dangerous as it could be hard to predict vehicle's next movement and uncomfortable to passengers.

Method to dynamically adjusting speed control rates of autonomous vehicles


A small-sized, front-end module is offered which is for use in a wireless communication device such as a mobile phone and which can suppress harmonics to a sufficiently low level. The front-end module has at least a switching circuit for switching one antenna between a transmiting system and a receiving system, a power amplifier for power-amplifying a transmission signal, and a low-pass filter inserted between the switching circuit and power amplifier. These components are integrated. A first kind of harmonics is produced from the switching circuit toward the power amplifier and reflected by the low-pass filter. A second kind of harmonics is produced from the power amplifier toward the antenna. A third kind of harmonics is produced from the switching circuit toward the antenna. The third kind of harmonics is canceled by the reflected first kind of harmonics and the second kind of harmonics.

The present invention relates to the front-end module of a wireless communication device using a send-receive shared antenna and, more particularly, to a front-end module that can be used in a wireless communication device which is applicable for plural communication systems and which makes a switch between plural send and receive signals by a switching circuit connected with a send-receive shared antenna to reduce harmonics radiated from the antenna during transmission. The invention also relates to a communication terminal using this front-end module.
In a terminal device of a wireless communication device as used in mobile communications such as a cellular phone or mobilephone, the sending and receiving systems share one antenna. In this case, a switching circuit is usually inserted between the antenna and the sending and receiving systems. During transmission, the antenna is switched to the transmiting system. During reception, the antenna is switched to the receiving system.
In the terminal device constructed in this way, when transmission is made, an RF send signal produced by the sending circuit of the transmiting system is propagated to the antenna through the switching circuit Then, the signal is radiated as an electromagnetic signal into the air by the antenna. During reception, an RF signal received by the antenna is supplied to the receiving circuit of the receiving system through the switching circuit.
The switching circuit uses a semiconductor device. Even where the sending circuit does not produce harmonics, if a large power such as more than 30 dBm is passed through the switching circuit, harmonics are produced due to nonlinearity of the switching circuit itself.
A configuration in which a filter (such as a low-pass filter for filtering out harmonics) is placed between the switching circuit and the antenna is conceivable as a method of suppressing the harmonics during transmission. However, this provides a loss to the receiving circuit and hence is disadvantageous. In addition, it is theoretically difficult to cope with plural communication systems. For example, there are the following problems. The second harmonic (1800 MHz) of GSM (900 MHz) is close to the fundamental wave of DCS (1750 MHz). The third harmonic (2400 MHz) of GSM (800 MHz) is close to the fundamental wave of PCS (1950 MHz).
Another method of suppressing harmonics during transmission uses a circuit proposed in Japanese Patent Publication JP-A-2001-86026. FIG. 5 is a conceptual view illustrating the manner-in which harmonics from a switching circuit SW are suppressed by a low-pass filter LPF positioned between the switching circuit SW and a transmiting system as shown in the Japanese publication. In FIG. 5, the switching circuit SW produces harmonics toward the antenna and toward the transmiting system at the same time. That is, harmonics (A) are produced toward the antenna. Harmonics (B) are produced toward the transmiting system. If the harmonics (B) traveling toward the transmiting system are well adjusted in phase and reflected by the low-pass filter LPF, the harmonics (B) cancel the harmonics (A) traveling toward the antenna. Thus, the harmonics radiated from the antenna ANT can be weakened.
The conventional circuit described in connection with FIG. 5 can weaken the harmonics on the antenna side to some extent but cannot completely cancel them out. For example, the harmonics suppression level requirement on mobile phones cannot be satisfied in some cases. It is considered that the cause is that when reflection waves (B′) produced by reflecting harmonics (B) traveling toward the transmiting system by a low-pass filter LPF and harmonics (A) traveling toward the antenna are superimposed, they can be put 180° out of phase but cannot be made equal in amplitude, for the following reasons.
(1) Because of asymmetry of the switching circuit SW, the produced levels of harmonics are asymmetric between the input and output ends of the switching circuit SW.
(2) Because the low-pass filter LPF cannot be made loss less, the reflected waves (B′) are smaller in amplitude than the harmonics (B).
(3) Because the reflected waves (B′) attenuate further due to the loss in the switching circuit SW and become reflected waves (B″), when these waves are superimposed with the harmonics (A) in practice, the amplitude is reduced further.

Front-end module and communication terminal


A feeder is disposed along a guide rail that guides an electrically powered vehicle. The electrically powered vehicle has an electric power receiving unit that surrounds the feeder on a non-contact basis. Electric power is supplied from the feeder to the electrically powered vehicle through electric power receiving units. The number of electric power receiving units is two. Each of the electric power receiving units has a mechanism that causes the electric power receiving unit to be inclined in the tangent direction of the feeder at a curved portion of the guide rail in such a manner that the distance between the feeder and the electric power receiving unit is kept so that optimum power can be obtained.

1. Field of the Invention
The present invention relates to a non-contact type electric power supplying system for supplying electric power to an electrically powered vehicle on a non-contact basis.
2. Description of the Related Art
Electrically powered vehicles, such as transportation means such as electric train carriages and monorails, and self-guided vehicles that carry parts and so forth in factories, and so forth are known.
As one means for supplying electric power to such electrically powered vehicles, a charging station system has been implemented for electric vehicles. However, in the charging station system, whenever the electric power of the battery of the vehicle begins to run out, the user thereof should drive the vehicle to a charging station and charge it with electric power. Thus, when a parts conveying system in a factory is operated using such a charging system, the operating efficiency is low.
To solve this problem, an electric power supplying system is used. In the electric power supplying system, as in monorails, a contact-type of electric power supplying system has been proposed. However, in this system, since the contact portions get worn, they should be maintained and periodically replaced with new ones. Moreover, in the contact-type electric power supplying system, since the contact portions are subject to sparking, such a system cannot be used in an explosion-protected area.
To solve such problems, non-contact type electric power supplying systems have been proposed. FIG. 1 is a schematic diagram of a conventional non-contact type power supplying system. In FIG. 1, a guide rail 1 is disposed and supported by a rail support member 1a on a ceiling or the like. A vehicle 2 that is suspended and moved by a roller (not shown) is disposed on the guide rail 1. An electric power receiving unit 3 is disposed in the vehicle 2. The electric power receiving unit 3 is mounted on the vehicle 2 through a base portion 5 supported with a shaft 4.
FIG. 2 is a sectional view taken along lines 2--2 of FIG. 1. FIG. 2 shows a cross section of the guide rail 1 and the electric power receiving unit 3. The guide rail 1 has a bracket "!" shaped section. Two feeders 6 are disposed on a side surface of the guide rail 1 and supported by support members 7. In other words, the feeders 6 are located along the guide rail 1. The electric power receiving unit 3 has an E-shaped section. A secondary coil 9 is disposed at a center convex portion of the electric power receiving unit 3. The electric power receiving unit 3 is made of silicon steel. Each of the feeders 6 is located within the respective concave portions of the E-shaped section of the electric power receiving unit 3.
When an AC current with a predetermined frequency (for example, 10 kHz) is supplied to the feeders 6 from an AC power supply (not shown), a voltage is induced in the secondary coil 9 of the electric power receiving unit 3. In other words, when an AC current with a predetermined frequency is supplied to the feeders 6, a magnetic circuit is formed around the feeders 6 through the electric power receiving unit 3 and a part of the guide rail 1. Thus, a voltage is induced in the secondary coil 9 due to electromagnetic induction. The voltage (electric power) obtained in such manner is used to move the vehicle 2.
The voltage induced by the secondary coil 9 is obtained by an AC magnetic field that generates a high frequency current that flows in the feeders. Thus, when the distance between the feeders 6 and the electric power receiving unit 3 (for example, the distance L from an edge surface of the electric power receiving unit 3 to the feeders 6 shown in FIG. 2) varies, the induced voltage varies. When the guide rail 1 is straight, the distance between the feeders 6 and the electric power receiving unit 3 is nearly constant. Thus, the voltage induced by the secondary coil 9 does not appreciably deviate.
However, since the guide rail 1 is disposed in, for example a factory, it has a curved portion as well as a straight portion. For example, as shown in FIG. 1, as with a corner portion of a conveying system, the guide rail 1 has a curved portion. The above-described distance L deviates by +.DELTA.L or -.DELTA.L. This deviation is proportional to the length of the electric power receiving unit 3 (namely, the length B of the core of the electric power receiving unit 3 (see FIG. 1)). Thus, the induced voltage decreases corresponding to the amount of the deviation.
In other words, as shown in FIG. 1, the electric power receiving unit 3 has a predetermined length B in the moving direction of the vehicle 2. Thus, when the vehicle 2 passes through the corner portion, the relative position of the feeders 6 within the electric power receiving unit 3 is denoted by a curved feeder line 6 shown in FIG. 3. On the other hand, assuming that an optimum position in which the electric power receiving unit 3 most effectively receives electric power from the feeders 6 is in the range denoted by dashed lines shown in FIG. 4, the corner portions 3a and 3b of unit 3 as shown in FIG. 3 are not preferable for the electric power receiving unit 3 to receive electric power (the dashed lines shown in FIG. 3 correspond to the optimum position shown in FIG. 4). Thus, a leakage flux or the like increases and thereby sufficient electric power cannot be supplied to the vehicle 2.

Non-contact electric power supplying system for a vehicle

Kabushiki Kaisha Toyoda Jidoshokki Seisakusho


A method for drilling a wellbore includes drilling the wellbore by injecting drilling fluid into a top of a tubular string disposed in the wellbore at a first flow rate and rotating a drill bit. The tubular string includes: the drill bit disposed on a bottom thereof, tubular joints connected together, a longitudinal bore therethrough, a port through a wall thereof, and a sleeve operable between an open position where the port is exposed to the bore and a closed position where a wall of the sleeve is disposed between the port and the bore. The method further includes moving the sleeve to the open position; and injecting drilling fluid into the port at a second flow rate while adding a tubular joint(s) to the tubular string. The injection of drilling fluid into the tubular string is continuously maintained between drilling and adding the joint(s).

1. Field of the Invention
The present invention relates to continuous flow drilling systems and methods.
2. Description of the Related Art
In many drilling operations in drilling in the earth to recover hydrocarbons, a drill string made by assembling pieces or joints of drill tubulars or pipe with threaded connections and having a drill bit at the bottom is rotated to move the drill bit. Typically drilling fluid, such as oil or water based mud, is circulated to and through the drill bit to lubricate and cool the bit and to facilitate the removal of cuttings from the wellbore that is being formed. The drilling fluid and cuttings returns to the surface via an annulus formed between the drill string and the wellbore. At the surface, the cuttings are removed from the drilling fluid and the drilling fluid is recycled.
As the drill bit penetrates into the earth and the wellbore is lengthened, more joints of drill pipe are added to the drill string. This involves stopping the drilling while the tubulars are added. The process is reversed when the drill string is removed or tripped, e.g. to replace the drilling bit or to perform other wellbore operations. Interruption of drilling may mean that the circulation of the mud stops and has to be re-started when drilling resumes. This can be time consuming, can cause deleterious effects on the walls of the wellbore being drilled, and can lead to formation damage and problems in maintaining an open wellbore. Also, a particular mud weight may be chosen to provide a static head relating to the ambient pressure at the top of a drill string when it is open while tubulars are being added or removed. The weighting of the mud can be very expensive.
To convey drilled cuttings away from a drill bit and up and out of a wellbore being drilled, the cuttings are maintained in suspension in the drilling fluid. If the flow of fluid with cuttings suspended in it ceases, the cuttings tend to fall within the fluid. This is inhibited by using relatively viscous drilling fluid; but thicker fluids require more power to pump. Further, restarting fluid circulation following a cessation of circulation may result in the overpressuring of a formation in which the wellbore is being formed.
FIG. 1 is a prior art diagrammatic view of a portion of a continuous flow system. FIG. 1A is a sectional elevation of a portion of the union used to connect two sections of drill pipe, showing a short nipple to which is secured a valve assembly. FIG. 1B is a sectional view taken along the line 1B-1B of FIG. 1A.
A derrick 1 supports long sections of drill pipe 8 to be lowered and raised through a tackle having a lower block 2 supporting a swivel hook 3. The upper section of the drill string 8 includes a tube or Kelly 4, square or hexagonal in cross section. The Kelly 4 is adapted to be lowered through a square or hexagonal hole in a rotary table 5 so, when the rotary table is rotated, the Kelly will be rotated. To the upper end of the Kelly 4 is secured a connection 6 by a swivel joint 7. The drill pipe 8 is connected to the Kelly 4 by an assembly which includes a short nipple 10 which is secured to the upper end of the drill pipe 8, a valve assembly 9, and a short nipple 25 which is directly connected to the Kelly 4. A similar short nipple 25 is connected to the lower end of each section of the drill pipe.
Each valve assembly 9 is provided with a valve 12, such as a flapper, and a threaded opening 13. The flapper 12 is hinged to rotate around the pivot 14. The flapper 12 is biased to cover the opening 13 but may pivot to the dotted line position of FIG. 1A to cover opening 15 which communicates with the drill pipe or Kelly through short a nipple 25 into the screw threads 16. The flapper 12 is provided with a screw threaded extension 28 which is adapted to project into the threaded opening 13. A plug member 27 is adapted to be screwed on extension 28 as shown in FIG. 1A, normally holding the valve 12 in the position covering the side opening in the valve assembly. Normally, before drilling commences, lengths of drill pipe are assembled in the vicinity of the drill hole to form "stands" of drill pipe. Each stand may include two or more joints of pipe, depending upon the height of the derrick, length of the Kelly, type of drilling, and the like. The sections of the stand are joined to one another by a threaded connection, which may include nipples 25 and 10, screwed into each other. At the top of each stand, a valve assembly 9 is placed. It will be observed that the valve body acts as a connecting medium or union between the Kelly and the drill string.
Normally, oil well fluid circulation is maintained by pumping drilling fluid from the sump 11 through pipe 17 through which the pump 18 takes suction. The pump 18 discharges through a header 39 into valve controlled flexible conduit 19 which is normally connected to the member 6 at the top of the Kelly, as shown in FIG. 1. The mud passes down through the drill pipe assembly out through the openings in the drill bit 20, into the wellbore 21 where it flows upwardly through the annulus and is taken out of the well casing 22 through a pipe 23 and is discharged into the sump 11. The Kelly 4, during drilling, is being operated by the rotary table 5. When the drilling has progressed to such an extent that is necessary to add a new stand of drill pipe, the tackle is operated to lift the drill string so that the last section of the drill pipe and the union assembly composed of short nipple 25, valve assembly 9, and short nipple 10 are above the rotary table. The drill string is then supported by engaging a spider (not shown).
The plug 27 is unscrewed from the valve body and a hose 29, which is controlled by a suitable valve, is screwed into the screw threaded opening 13. While this operation takes place, the circulation is being maintained through hose 19. When connection is made, the valve controlling hose 29 is opened and momentarily mud is being supplied through both hoses 19 and 29. The valve controlling hose 19 is then closed and circulation takes place as before through hose 29. The Kelly is then disconnected and a new stand is joined to the top of the valve body, connected by screw threads 16. After the additional stand has been connected, the valve controlling hose 19 is again opened and momentarily mud is being circulated through both hoses 19 and 29. Then the valve controlling hose 29 is closed, which permits the valve 12 to again cover opening 13. The hose 29 is then disconnected and the plug 27 is replaced.

Continuous flow drilling systems and methods


A linerless tank structure has a body that defines an enclosed interior volume. The body has a cylindrical section having an axis of symmetry and a dome section coupled with the cylindrical section. The construction of the pressure vessel includes multiple fiber plies. At least one of the fiber plies is a helical ply having fibers traversing the dome helically about the axis of symmetry. At least a second of the fiber plies is a braided or woven ply.

This application relates primarily to pressure vessels. More specifically, this application relates to composite-overwrapped pressure vessels and all-composite pressure vessels. This application also relates to composite-overwrapped and all-composite tanks for storage of liquids and/or gases at relatively low pressures.
Pressure vessels and storage tanks find application in a wide assortment of industries. In certain industries, there is a particularly acute need for the pressure vessels to be of light weight. Some examples of these applications include the use of pressure vessels in self-contained breathing apparatus (SCBA) and gaseous fuel storage systems for automobiles, such as storage of compressed natural gas or hydrogen gas. In other applications, lightweight composite pressure vessels and storage tanks may be used on aircraft, launch vehicles, and spacecraft for chemical storage, transport, and/or mixing.
There are a number of different types of structures used for pressure vessels and storage tanks. Using a nomenclature common in the art, Type-I pressure vessels are fabricated of metal, Type-II pressure vessels are partially overwrapped metallic tanks, Type-III pressure vessels are composite-overwrapped structures that are lined with metal, and Type-IV pressure vessels are composite-overwrapped structures that are lined with a polymer. Of particular interest are "Type-V" pressure vessels, which are defined here as all-composite pressure vessels. Such pressure vessels may be especially suitable for lightweight applications like those identified above because they are projected to provide a weight reduction up to 25% when compared with conventional metal- or polymer-lined pressure vessels. Furthermore, Type-V pressure vessels have the potential of being manufactured more cheaply than Type-III and Type-IV pressure vessels due to the elimination of costly metal or polymer liners.
The composite outer layer on conventional composite-overwrapped pressure vessels with either metallic or polymeric liners is typically designed to safeguard against structural failure by rupture, while the liner is designed to contain the enclosed fluid. This effectively decouples the structural design of the pressure vessel from its fluid-containment requirements. There are three practical results of this decoupling of design requirements. First, the liners in Type-III and Type-IV pressure vessels are not mass-efficient in reacting the internal pressure load of the pressure vessel, which makes the liners a source of parasitic weight. Second, essentially the mode of failure in all lined pressure vessels (i.e., Type-III and Type-IV) when over-pressurized is catastrophic rupture of the structural shell—rather than leakage through the liner. However, for many applications, "leak-before-burst" failure performance, both under monotonic and cyclic pressurization, is desirable because it greatly reduces the likelihood of catastrophic failures of pressure vessels resulting in injury or death. Third, the liners in Type-III and Type-IV pressure vessels are, by definition, made of different materials than the composite outer shells. Hence, Type-III and Type-IV pressure vessels have performance limitations due to their use of dissimilar materials (e.g., limitations due to differential thermal-expansion, buckling and galvanic corrosion effects).
To address the first result above and in order to minimize the weight of composite pressure vessels, it is desirable to either eliminate the liner, or make the liner from a composite material that participates in reacting the internal pressure load in a mass efficient manner, while also preventing leakage of the contents.
To address the second result above and in order to design composite pressure vessels to exhibit a benign "leak-before-burst" failure mode, it is desirable to either eliminate the liner or design the liner such that it fails, predictably, before the composite outer shell fails.
To address the third result above and in order to eliminate performance limitations due to the use of dissimilar materials, it is desirable to either eliminate the liner or design the liner using a composite material that provides similar thermal, electrical and mechanical performance to the composite material used in the outer shell.
Past efforts to develop linerless composite pressure vessels and composite liners for composite-overwrapped pressure vessels have resulted in some successes. However, performance limitations of typical composite materials (i.e., lower-than-desired design operating strains) have typically resulted in higher-than-desired weights and/or un-predictable leakage and failure performance, in the case of linerless composite pressure vessels. Similarly, inadequate design, lack of precise failure prediction and improper material selection have resulted in composite liners that represent only an incremental improvement over traditional polymer and metallic liners.
There is accordingly a general need in the art for improved composite-lined and linerless, all-composite pressure vessel structures.

Damage and leakage barrier in all-composite pressure vessels and storage tanks


An elongate article holding package for a wiper blade having a pair of package panels with at least one of the panels including a blade beam receiving seat and a support flat upon which part of the blade rests during packaging. When closed, the flats position and can clamp the blade therebetween. In a preferred embodiment, both panels are so configured and preferably include one or more longitudinal stiffeners that oppose bending moments created by force transmitted to the package by the blade beam. The package preferably is of tri-fold construction having a spine that is spaced from and protects the wiper element. The spine preferably includes at least a plurality of spaced apart longitudinally extending stiffeners. One or more stiffening flanges preferably are also provided. When closed, the panels and spine advantageously cooperate with each other to increase package crush and bending resistance.

Beam-type windshield or windscreen wiper blades are growing in popularity throughout the United States and the world. Beam-type wiper blades have an elongate beam "backbone" that is curved along its length. They also have a rubber wiper element attached to one side of the beam and an adapter, used for releasably mounting the wiper blade to a vehicle, attached to the beam, extending outwardly from its other side. Examples of beam-type wiper blades are disclosed in U.S. Pat. Nos. 6,836,925, 6,813,923, and 6,550,096.
The curved beam helps ensure more constant and even pressure is applied along the entire windshield, providing a smoother, more consistent wipe. While conventional articulating framework wiper blades typically have somewhere around six or eight pressure points, beam-type wiper blades essentially have an infinite number of pressure points, helping to ensure the wiper element is urged against the windshield with substantially continuous pressure along substantially the entire length of the blade. A curved beam is also better able to conform to the curved contour of just about any vehicle windshield, which further ensures a smoother, more consistent wiping action.
During operation, each wiper blade is attached to an arm that moves back and forth across part of a windshield of a vehicle. The wiper element rides in concert along the surface of the windshield, essentially functioning as a squeegee to urge water in its path off the windshield.
Packaging such a beam-type windshield wiper blade poses unique challenges as compared to conventional wiper blades because of its curved beam. One challenge relates to the fact that beam-type wiper blades are significantly wider than conventional wiper blades. For example, where a conventional blade typically has a maximum transverse width no greater than three inches, a beam-type blade has a greater maximum transverse width that can be as wide as four or five inches.
Another challenge relates to protecting the wiper element. Due to the curvature of the beam and the arrangement of the wiper element, the end of the wiper element can become warped or distorted over time if the blade is not properly supported. This can cause that part of the wiper element to make poor contact with the windshield, which can cause undesirable streaking during wiper operation. This warpage or distortion can also extend along part of the squeegee edge of the wiper element, making these problems even worse. If too great, it can undesirably result in such warped or distorted wiper blades being returned to the store for refund.
Accordingly, it would be desirable and advantageous to provide packaging for a beam-type wiper blade that protects the blade while minimizing the volume it occupies.


A photovoltaic system includes: a photovoltaic generator comprising strings that each includes one or more photovoltaic cells; a power converter; switches; and a controller. The power converter is configured to convert direct current (DC) power provided by the photovoltaic generator into alternating current (AC) power, and to output the AC power. Each switch is associated with one of the strings and is configured to connect the associated string to the power converter when set to a first setting, such that power generated by the first string can flow to the power converter. Each switch is also configured to disconnect the string from the power converter when set to a second setting. The controller is configured to control the power provided by the photovoltaic generator by selectively connecting the strings of the photovoltaic generator to the power converter by controlling the settings of the switches.

Photovoltaic systems use solar cells to convert light into electricity. A typical photovoltaic system includes several components, including photovoltaic cells, mechanical and electrical connections, mountings, and controllers for regulating and/or modifying the electrical current produced by the photovoltaic system.
The following terms are used herein to describe various components and/or operational aspects of photovoltaic systems:
PV photovoltaic
DC direct current
AC alternate current
VOC open circuit voltage
VGRID grid voltage
VNOM nominal grid voltage
IGRID grid current
FIG. 1 is a functional block diagram of a typical PV system 100. The photovoltaic system 100 includes a photovoltaic generator 101 that converts sunlight into electricity. In a conventional PV system, such as the photovoltaic system 100, the voltage generated by the system can be controlled by extracting an appropriate amount of power from the PV generator 101, passing the power from the PV generator 101 to a power converter 102 through to a power sink 103. According to an embodiment, the power converter 102 can comprise an electronic power converter. In a typical implementation, the power sink 103 is the electrical power grid (sometimes also referred to as the power "mains"). The grid comprises an electrical network for generating, transmitting, controlling, and distributing power from power generators to power consumers at various service locations across the network. The power converter 102 converts DC power provided by the PV generator 101 into AC power that can be distributed on the grid.
FIG. 2 is a more detailed block diagram of a conventional PV power system 200 that can be used to implement the system illustrated in FIG. 1. The PV power system 200 includes a solar cell array 201 that comprises solar cells (also referred to as photovoltaic cells). The solar cells are solid state devices that convert the energy of sunlight directly into electricity by the photovoltaic effect. The solar cells generate DC voltage.
The solar cell array 201 is coupled to a DC switch 202. The DC switch 202 can be closed to connect the solar cell array 201 to DC capacitor bank 204, or opened to disconnect the solar cell array 201 from the DC capacitor bank 204. When the DC switch 202 is closed and the solar cell array 201 is generating power, the solar cell array 201 can provide power to charge the DC capacitor bank 204. The DC capacitor bank 204 is also connected to an inverter 205.
The inverter 205 converts the DC voltage output from the capacitor bank 204 into a 3-phase (or in some cases 2-phase) pulsed AC voltage. The inverter 205 outputs pulsed AC current to a filter 206. The filter 206 converts the pulsed AC current output by the inverter 205 into a sinusoidal AC voltage. The sinusoidal AC voltage can then be output to a mains power grid 209. If an AC mains switch 207 is closed, the sinusoidal AC voltage output by the filter 206 is received by the power transformer 208. The power transformer 208 adapts the voltage output by the PV system 200 to the grid voltage. This configuration allows the PV system 200 to output electricity onto the mains grid 209. The voltage output by the photovoltaic system 200 is no higher than the grid voltage.
Controlling the voltage generated by a PV generator such as the solar cell array 201 is important because it can help to (a) increase the power generated by the solar panels, and (b) reduce the voltage stress on the power converter. If the power sink 103, such as the grid 209, is unable to absorb the available power produced by the PV generator 101, the PV voltage will increase toward the open circuit level (VOC) and will ultimately produce an increased voltage stress on the power converter 102. In conventional systems, this is addressed by "overdesigning" the power converter, such that the power converter 101 can reliably operate with the PV open circuit voltage levels. Overdesigned systems have lower efficiency and higher complexity than systems that are not overdesigned.
FIG. 3 illustrates an alternative approach that conventional systems have used to address these issues. A PV power system 300 includes a pre-load 304 in the form of a dissipative resistive load parallel to a PV generator 301. In the event that a power sink 303 is unable to absorb the power generated by the PV generator 301, the pre-load 304 can be activated to supplement the power sink and to maintain the PV voltage at levels that are safe for power converter 302. The use of a pre-load 304, however, can be prohibitively expensive and can pose a fire risk.

Schneider Electric Solar Inverters USA, Inc.