A gain-stable npn heterojunction bipolar transistor includes a graded superlattice between its base and emitter consisting of multiple discrete periods, with each period having a layer of base material and another layer of emitter material. The thicknesses of the base material layers decrease while the thicknesses of the emitter material layers increase in discrete steps for each successive period from the base to the emitter. The thickness of each period is preferably at least about 20 Angstroms, with the superlattice including more than five periods. The superlattice is preferably doped to establish an electrical base-emitter junction at a desired location. The graded superlattice inhibits the diffusion of beryllium p dopant from the base into the emitter during transistor operation, thus stabilizing the device's gain and turn-on voltage.

1. Field of the Invention
This invention relates to heterojunction bipolar transistors (HBTs) with a graded superlattice between the base and emitter.
2. Description of the Related Art
HBTs represent a field of increasing interest because of their potential for higher emitter efficiency, decreased base resistance, less emitter current crowding, improved frequency response and wider temperature range of operation. A representative HBT is illustrated in FIG. 1. It includes a semi-insulating semiconductor substrate 2, typically InP or GaAs. A highly doped n.sup.+ subcollector layer 4 on the substrate provides an underlying contact with the more lightly n.sup.- doped collector layer 6, with a metallized or highly doped semiconductor pad 8 providing a collector contact through the subcollector. A p.sup.+ base layer 10 is formed over the collector, with an n doped emitter 12 over the central portion of the base and a lateral base contact 14 surrounding the emitter. An emitter contact 16 is provided on the emitter's upper surface.
During the operation of the HBT, the input voltage forward-biases the base-emitter junction, allowing electrons from the n-type emitter to enter the base. The injected electrons travel across the base by diffusion or drift, and are swept into the collector when they reach the base-collector junction by the high fields in this region. In a homojunction bipolar transistor there is a flow of holes from the base into the emitter across the forward biased base-emitter junction. To suppress the reverse hole injection, the base doping is made lower than that of the emitter. This, however, makes the base layer more resistive, thereby increasing the device's overall base resistance and degrading its bandwidth. In an HBT, by contrast, a wide-bandgap emitter material is used that creates a higher energy barrier for hole injection into the emitter than the barrier to electron flow into the base, thereby automatically suppressing the base current that is due to hole injection. The doping of the base layer can be made as large as possible from solid state chemistry considerations, and the base resistance is correspondingly reduced.
To achieve the high base dopings necessary for RF performance, typically 5-10.times.10.sup.19 cm.sup.-3, beryllium is widely used as the p-type base dopant for npn HBTs. A significant reliability issue with such devices is that the electric currents and fields generated at the base-emitter junction cause Be to diffuse from the base into the emitter. This movement of Be is characterized by an increase in the emitter-base turn-on voltage as the electrical junction (defined as the location where the Be doping from the base meets the emitter doping) is pushed further into the emitter. The Be penetration leads to decreased gain, and eventually to complete failure of the transistor. This degradation mechanism is currently the operating rate limiting failure mechanism of npn AlInAs/GaInAs HBTs.
One approach to solving the Be diffusion problem uses an undoped layer of low bandgap material, such as GaInAs or GaAs about 100-500 Angstroms thick, between the wide bandgap emitter and the low bandgap base. The undoped layer acts as a buffer region into which the base Be can diffuse, so that the bulk of the diffusing Be does not reach the emitter. This technique is described in Malik et al., "High-gain, high frequency AlGaAs/GaAs graded band-gap base bipolar transistors with a be diffusion set back layer in the base", Applied Physics Letters, Vol. 46, No. 6, pages 600-602 (1985), and in Jalali et al., "New ideal lateral scaling in abrupt AlInAs.InGaAs heterostructure bipolar transistors prepared by molecular beam epitaxy", Applied Physics Letters, Vol. 54, No. 23, pages 2333-2335 (1989). Undoped setback or spacer layers of base material between the base and emitter are also disclosed in Jensen et al., "AlInAs/GaInAs HBT Ic Technology", IEEE Journal of Solid-State Circuits, Vol. 26, No. 3, March 1991, pages 415-421, and in Nottenburg et al., "InP-Based Heterostructure Bipolar Transistor", Proc. of the 1989 GaAs IC Symposium, 1989 pages 135-138. The setbacks, however, simply increase the distance that Be must diffuse before it penetrates into the emitter, and do not act to actually inhibit the Be movement. Furthermore, the electron transit time through the material increases with the width of the setback layer, and this in turn slows the speed of the HBT.
As the present invention employs a form of graded superlattice between the base and emitter to block Be diffusion, it would be helpful to briefly review the graded superlattice structure. Graded superlattices have previously been used to eliminate the interface pile-up effect of holes in a "high-low" InP/GaInAs avalanche photodiode (Capasso et al., "Pseudo-quaternary GaInAsP semiconductors: A new Ga.sub.0.47 In.sub.0.53 As/InP graded gap superlattice and its applications to avalanche photodiodes", Applied Physics Letters, Vol. 45, No. 11, Dec. 1, 1984, pages 1193-1195), and to minimize the effect of carrier trapping at the AlInAs/GaInAs interface of a metal-semiconductor-metal photodiode (Wada et al., "Very high speed GaInAs metal-semiconductor-metal photodiode incorporating an AlInAs/GaInAs graded superlattice", Applied Physics Letters, Vol. 54, No. 1, 2 January, 1989, pages 16-17). They consist of a series of layer pairs interfacing between first and second material, with each pair having one layer of the first material and another layer of the second material. Although the total pair thickness generally remain uniform, the thickness of each of the two layers varies from pair to pair. At the end of the superlattice adjacent the first material, the thickness of the layer formed from that material is at a maximum, while the thickness of the second material layer is minimum. These thicknesses are graded across the superlattice, so that at its opposite end the thickness of the first material layer is at a minimum and the thickness of the second material layer is at a maximum.
Graded superlattices have not previously been used in an HBT to block the diffusion of a base dopant. In Won et al., "Self-Aligned In.sub.0.52 Al.sub.0.48 As/In.sub.0.53 Ga.sub.0.47 As Heterojunction Bipolar Transistors with Graded Interface on Semi-Insulating InP Grown by Molecular Beam Epitaxy", IEEE Electron Device Letters, Vol. 10, No. 3, March 1989, pages 138-140, a graded interface is provided between the base and emitter that makes a linear and continuous transition from the base to the emitter material. This is accomplished in a molecular beam epitaxy (MBE) system by progressively increasing the temperature of the emitter material cell and reducing the temperature of the base material cell as the epitaxial growth from the base to the emitter proceeds. With an InGaAs base and InAlAs emitter, compositional grading of a base-emitter interface was achieved by simultaneously raising the Al and lowering the Ga cell temperatures, while keeping the total Group III flux constant. Graded interfaces of this type have been used to avoid conduction spikes at the base-emitter junction, and thus enhance charge transport and current gain, but do not solve the Be diffusion problem. Furthermore, it is difficult to cool the cell for the base material fast enough for a typical MBE growth rate of 100 Angstroms per minute; with typical cell temperatures of about 1,040.degree. C. for Al and 880.degree. C. for Ga, it would be necessary to reduce the cell temperature by about 100.degree. C. to reduce the flux from that cell by 90%.
In Asbeck et al., "InP-based Heterojunction Bipolar Transistors: Performance Status and Circuit Applications", Second Int'l. Conf. on Indium Phosphide and Related Materials, Apr. 23-25, 1990, pages 2-5, a short period superlattice was formed between an AlInAs emitter and a GaInAs base. The superlattice consisted of four sections, with each section having four identical periods; each period had a thickness of 12 Angstroms. In the first section adjacent the emitter, the four periods each had AlInAs and GaInAs layers with widths in the ratio 4:1; the width ratio was reduced to about 3:2 for each of the identical periods in the second section, to about 2:3 for the identical periods in the third section, and to about 1:4 for the identical periods in the fourth section closest to the base. This type of superlattice was proposed as an alternative to a continuous grading, because of problems in the precise control over the continuous grading process. There was no claim to any reduction in the field-enhanced diffusion of Be from the base, and in fact the present invention has found the Asbeck et al. superlattice structure to not be oriented towards a reduction of Be diffusion. The very narrow widths of the minority material layers in the sections at each end of the superlattice, on the order of 1.25 Angstroms, have not been found to be effective in reducing Be diffusion. Since a reduction in Be diffusion is a well known and important goal for an HBT with this type of material system, the lack of any reference to such a reduction indicates that no significant reduction in Be diffusion actually occurred.

Gain-stable NPN heterojunction bipolar transistor


A system and method of managing assets using a combined electronic article surveillance (EAS) and barcode scanning device. The combined EAS/Scanner is portable and wirelessly connected to a network for facilitating a number of asset management functions, including personal shopping, pre-checkout, data mining, and inventory tracking.

A variety of EAS systems are well known for the prevention or deterrence of unauthorized removal of articles from a controlled area. In a typical EAS system, tags designed to interact with an electromagnetic field located at the exits of the controlled area are attached to articles to be protected. If a tag is brought into the electromagnetic field or "interrogation zone", the presence of the tag is detected and appropriate action may be taken. For a controlled area such as a retail store, the appropriate action taken for detection of an EAS tag may be the generation of an alarm. Some types of EAS tags remain attached to the articles to be protected, but are deactivated prior to authorized removal from the controlled area by a deactivation device that changes a characteristic of the tag so that the tag will no longer be detectable in the interrogation zone.
The majority of EAS tag deactivation devices are fixed at a specific location, such as adjacent a point-of-sale (POS) station in a retail environment. A barcode scanner may also be located at the POS station for scanning a barcode affixed to the article. Barcode systems and scanners are well known. Barcodes may be used for a variety of purposes, such as inventory control and for managing POS transactions. In a typical POS transaction, upon purchase of an article, the barcode is scanned at a POS station. The barcode represents a reference number that is communicated to a computer to look up an associated record containing descriptive data such as product name, vendor name, price, quantity-on-hand, etc. The computer does a "price lookup" and displays the price on the cash register. The computer may also subtract the quantity purchased from the quantity-on-hand and perform other informational or management functions related to the purchased products.
When it is determined that the article is authorized for removal from the controlled location, e.g. after a proper purchase, any EAS tag affixed to the article is deactivated. If an EAS tag is inadvertently not deactivated at the deactivator adjacent the POS station, the EAS tag will set off an alarm at the store exit. To then deactivate the EAS tag, the article must be returned to the deactivator adjacent the POS station, which causes customer confusion and embarrassment. In addition, if the purchased article has exhibited a history of avoiding deactivation, e.g. if a manufacturer has placed the tag in an inappropriate location in the article packaging, detection of this history is entirely subject to human efforts. As such, a history of deactivation failure for a particular device may go perpetually unnoticed and uncorrected.
The conventional orientation of the EAS deactivator and barcode scanner at the POS station has also placed significant practical limitations on activities such as scanning large or bulky items that do not physically fit into the area adjacent the POS station, customer self-checkout, and inventory tracking. Handheld devices including deactivators for RF type EAS tags and a barcode scanner have been developed. These devices have, however, been coupled to the POS station via power and data cables. Accordingly, they require the EAS tag be moved near the POS station, within range of the handheld scanner/deactivator cord, for scanning and deactivating. To date, no known system has allowed complete freedom of movement within a controlled area for barcode scanning and EAS tag deactivation.
Accordingly, there is a need for a system and method for managing assets using a portable, handheld combined EAS system and barcode scanner.

System and method for managing assets using a portable combined electronic article surveillance system and barcode scanner


Provided in the embodiments of the present disclosure are methods for transmitting and receiving an SRS, and related devices. The method includes: receiving indication information transmitted by a base station and used to indicate a PRB bundling size; and transmitting, within at least one PRB bundle, the SRS to the base station, wherein the number of PRBs included in the at least one PRB bundle is equal to the PRB bundling size, and a same precoding is used by PRBs belonging to a same PRB bundle, and the precoding is determined by the UE itself.

In a communication system, a User Equipment (UE) needs to transmit an SRS to a base station to obtain an uplink Channel Quality Indicator (CQI). At present, before the UE transmits the SRS, it needs to receive a Precoding Matrix Indicator (PMI) transmitted by the base station, and receive SRS configuration information transmitted by the base station, and then transmit the SRS on a Physical Resource Block (PRB) corresponding to the SRS configuration information using a precoding indicated by the PMI. The base station performs channel estimation in a PRB by PRB manner after receiving the SRS, which results in lower performance of the channel estimation.

Method for transmitting SRS, method for receiving SRS, and related devices


A polygon mirror is made up of a rotor including a ceramic ring, a yoke and a mirror surface formation member. The yoke and the mirror surface formation member are secured to an outer periphery of the ceramic ring. A radial dynamic pressure bearing is defined by an inner periphery of the ceramic ring and an outer periphery of the fixing shaft. A thrust dynamic pressure bearing is defined by both end surfaces of the ceramic ring and surfaces of a thrust plate fixedly secured to the stator and confronting both end surfaces of the ceramic ring. The ceramic ring, the yoke and the mirror surface formation member are integrated by the material making up the mirror surface formation member during the molding of the member to form the rotor.

Field of the Invention
The present invention relates to a polygon mirror serving as a rotor in a polygon mirror scanning motor.
Prior Art
FIG. 2 is a sectional view of such a rotor in a conventional polygon mirror scanning motor. In FIG. 2, reference numeral 1 denotes a ceramic ring. A yoke 2 is shrink-fitted onto the ceramic ring 1. Then, a higher degree of planeness and surface roughness are imparted to the surfaces of the yoke 2 and a yoke 5 which are to contact a mirror surface formation member 3 defining a mirrored surface 4. The mirror surface formation member 3 is firmly clamped between the yoke 2 and the yoke 5 with a plurality of screws 16. Furthermore, a rotor magnet 6 having a plurality of magnetic poles of the motor is fixedly secured to the underside of the yoke 5.
FIG. 3 is a sectional view of a polygon mirror scanner motor employing the rotor shown in FIG. 2. A supporting shaft 8 fixed to a mount 7 extends through the ceramic ring 1. A radial bearing member 9 is firmly secured to the supporting shaft 8 and the ceramic ring 1. Moreover, thrust plates 10 and 11 are fixedly secured to the supporting shaft 8 so as to confront top and bottom end surfaces of the ceramic ring 1, respectively. A thrust dynamic pressure bearing is defined by the top and bottom end surfaces of the ceramic ring 1 and the respective confronting surfaces of the thrust plates 10 and 11. A radial dynamic pressure bearing is defined by the inner periphery of the ceramic ring 1 and the outer periphery of the radial bearing member 9. Reference numeral 12 designates a fixing bolt for fixing the thrust plates 10 and 11, the radial bearing member 9, and mounting plate 13 to the supporting shaft 8. A stator coil 14 is arranged on the top surface of the mount 7 so as to confront the rotor magnet 6. Reference numeral 15 indicates a cover.
In the above-described polygon mirror scanner motor, when the stator coil is sequentially energized, the inner periphery of the ceramic ring 1 of the rotor is supported on the radial bearing member 9, and the top and bottom end surfaces of the rotor are supported on the confronting surfaces of the thrust plates 10 and 11 for rotation. It is to be noted that the supporting shaft 8 and the radial bearing member 9 are collectively referred to as a fixing shaft, although the supporting shaft 8 may solely (without the radial bearing member 9) comprise the fixing shaft. In this case, the fixing shaft (supporting shaft) serves also as the radial bearing member.
The conventional rotor, that is, the polygon mirror described above, has the following disadvantages.
(1) Since the yoke 2 is shrink-fitted onto the ceramic ring 1, the outer diameter of the ceramic ring 1 and the inner diameter of the yoke 2 must be finished with a higher degree of roundness, concentricity, surface roughness, and dimensional tolerances, which contributes to high machining costs for the ceramic ring 1 and the yoke 2.
(2) Furthermore, after the shrink-fitting of the yoke 2 onto the ceramic ring 1, the surface of the yoke 2 in contact with the mirror surface formation member 3 must be subjected to a secondary machining operation to obtain strict planeness and surface roughness. Additionally, an additional assembly step is created by the need to thread the screw 16, securing the mirror surface formation member 3 to the yoke 5, with a predetermined controlled torque. Moreover, the rotor as a whole might be unbalanced due to looseness in the fitting section which is inevitably created in the assembly irrespective of the dimensional accuracy of the parts themselves, requiring numerous steps to correct the imbalance.
(3) Furthermore, depending on the degree to which the screw 16 is tightened, the mirror surface 4 may present a minute deformation, which in particular exerts a remarkable adverse influence, at the time of actual rotation, on the surface stability and jitter characteristic of the motor. The mirror surface formation member 3 must be provided with several through-holes for receiving several screws, thereby requiring a large number of machining steps, including the steps of processing the corners after the holes are formed. As a result, the manufacturing cost of the mirror is high.
(4) Moreover, the yoke 2 has a smaller height than the ceramic ring 1 when the shrink-fitting is performed, and hence only a portion of the ceramic ring is subjected to a shrink-fit. Thus, an uneven stress due to shrink-fitting is inevitably applied to the ceramic ring, which may possibly produce a crack in the ceramic ring 1 in an extreme case. In addition, the inner peripheral surface and the top and bottom surfaces of the ceramic ring 1 are liable to be deformed, which results in uneven thrust clearance and radial clearance between the rotor and the stator when incorporated into the scanner motor, which in turn adversely influences the rotational displacement of the motor. This is a cause of poor surface stability and jitter characteristic of the motor.


A planar gradient magnetic field assembly (20) selectively causes gradient magnetic fields linearly across the examination region (12) of a magnetic resonance imaging apparatus. The gradient coil assembly includes a pair of planar y gradient coils (22a, 22b) and a pair of planar x gradient coils (24a, 24b). On each plane, the gradient coil winding includes a pair of larger, outer coil loop arrays (60, 62). A pair of smaller inner coil loop arrays (66, 68) produce a first order gradient field correction to improve the accuracy of the gradient field. The coil loop arrays are symmetric relative to the z axis and relative to an (x,y) plane of symmetry perpendicular to the z axis.

The present invention relates to the art of magnetic field gradient generation. It finds particular application in conjunction with establishing gradient magnetic fields in magnetic resonance imaging techniques and will be described with particular reference thereto. It is to be appreciated, however, that the invention will also find application in spectroscopy and other processes and apparatus in which accurately predictable magnetic field gradients are established or maintained.
In magnetic resonance imaging, a uniform magnetic field is created through an examination region in which a subject to be examined is disposed. A series of radio frequency pulses and magnetic field gradients are applied to the examination region. Gradient fields are conventionally applied as a series of gradient pulses with preselected profiles. These pulses excite magnetic resonance, phase and frequency encode the resonance, and cause phase and frequency encoded magnetic resonance signals to be emitted.
More specifically, the gradient magnetic pulses are applied to select and encode the magnetic resonance signals. In some embodiments, the magnetic field gradients are applied to select one or more planes or slices to be imaged. Gradient field pulses are also applied for selectively modifying the uniform magnetic field to encode frequency and phase into the magnetization, hence the resonance signals in order to identify a spatial location.
The magnetic resonance signals are then processed to generate two or three dimensional image representations of a portion of the subject in the examination region. The accuracy of the resultant image representation, among other factors, is dependent upon the accuracy with which the actually applied magnetic field gradient pulses conform to selected gradient pulse profiles.
Heretofore, linear magnetic filed gradients have been produced by cylindrical gradient field coils. Discrete coils were wound in a bunched or distributed fashion on a large diameter hollow right cylinder tube, commonly 65 centimeters in diameter or larger. Conventional bunched geometries include Maxwell or modified-Maxwell pair for z-gradient production and single or multi-arc Golay saddle coils for x and y gradient production. The coils are normally wound in a series arrangement and positioned to give a magnetic field profile with the desired linearity over a predefined volume. The distributive windings on the right angle cylinders are generally would and in pairs and driven anti-symmetrically. The coils are driven in an anti-symmetric manner such that only odd field derivatives are non-zero at the coil origin. The first derivative is the field gradient while the third and higher order derivatives represents distortion. If the diameter of the cylinder and coil placement are chosen properly, the third derivative is cancelled at the origin making the fifth derivative the first distortion term.
The conventional gradient coils are constructed of copper buss bar or multi-strand wire that is would on a glass reinforced plastic tube. The inductance, which is related to the stored magnetic energy, is critical in gradient coil design. The inductance relates to how quickly the coil can switch the gradient field on and off with a given supply of voltage. Large inductances, as are typical in wound cylindrical coils, limit the switching speed of the gradient magnetic fields.
For maximum efficiency, it would be advantageous to reduce the diameter of the gradient coil cylinders to be as close as possible to the subject, provided gradient linearity can be maintained. The required energy for field gradient production varies roughly as a fifth power of a gradient coil cylinder diameter in free space. In an actual magnetic resonance imager, the gradient coils interact with other adjoining structures such as radiation shields of superconducting magnets, making the relationship somewhat greater than the fifth power. Although reducing the coil size could have a dramatic effect on power consumption, reducing the cylinder diameter below 65 centimeters would be too restrictive to receive patients for full body scans. Although less power consumptive, a single planar surface gradient coil, by contrast, suffers from poor gradient uniformity or field linearity. Images using a single planar gradient coil require geometric distortion correction for head size volumes and larger.
In accordance with the present invention, a new and improved gradient coil configuration is provided which overcomes the above referenced problems and others.

Biplanar gradient coil for magnetic resonance imaging systems


A portable, self-contained, electronic radioscopic imaging system uses a pulsed X-ray source, a remote X-ray sensor, and a self-contained, display and controller unit to produce, store, and/or display digital radioscopic images of an object under investigation in low voltage imaging environments such as medical applications including mammography and tissue imaging, and industrial radiography of low-density structures, or the like. The radiographic system uses an X-ray converter screen for converting impinging X-ray radiation to visible light, and thus each point impinged on the screen by X-ray radiation scintillates visible light emissions diverging from the screen. An image sensor, i.e., a CCD camera, is configured to sense the visible light from the screen. An aspheric objective lens operable with the CCD camera spatially senses visible light within a collection cone directed outwardly from the image sensor. An emission modification lens layer, e.g., a prismatic brightness enhancement film or a sprayed on transmissive layer, through which the visible light emitted from the screen is transmitted is superposed with the screen and positioned in an optical path between the aspheric lens and the screen for generally focusing the diverging visible light as a restricted cone of illumination propagating outwardly from each point impinged on the screen to increase the fraction of light directed into the collection cone of the first lens and reducing the amount of scattered visible light from the screen.

The present invention relates to a portable, self-contained, X-ray apparatus that digitally processes, displays, stores, and/or transmits electronic radioscopic images of sealed packages, containers, or other objects, or of patients and animals, on location for security, customs, medical, and other non-destructive and non-invasive purposes. More particularly, the present invention relates to an enhanced X-ray converter screen for use in X-ray radioscopic imaging systems which increases the detected brightness and reduces the effects of veiling glare and multiple reflections through the use of thin film lenslets or other light directing films or structures which simultaneously modify the emission angle of light from the screen and change its reflective characteristics to external light through the use of thin film lenslets or other light directing films or structures which simultaneously modify the emission angle of light from the screen and change its reflective characteristics to external light.
There are many instances in the medical, security or customs field when it is necessary to examine or inspect, in a non-invasive way, a patient, animal, or other living organism; or to examine and inspect, in a non-destructive way, the contents of a closed package, box, suitcase, or other container. Some of the general concerns and problems associated with such examinations or inspections are set forth in U.S. Pat. No. 5,608,774, incorporated herein by reference.
Where the imaging system uses an objective lens coupled through a collection cone to a phosphor X-ray conversion screen, as is common in many radioscopic imaging systems, there is a continuing need to improve the brightness and contrast of the displayed image. This is because such systems are premised on the assumption that all of the emitted light from the phosphor screen is collected into the collection cone of the objective lens, thereby providing a clear, sharp image of the emitted light. In practice, however, some of the emitted light is not collected into the collection cone and is scattered by objects within the imager enclosure back onto a different portion of the phosphor screen, from which location it is then diffusely reflected, with a fraction of the light being sent back into the collection cone. Since this light appears to originate from a differing point on the phosphor screen, it effectively reduces the true contrast of the image.
Virtually all optical designs are plagued by the problem of light outside of the capture cone of the lens hitting other features within the optical system and being scattered back into the image. Generally, prior art designs attempt to solve this problem by making the walls of the system physically distant from the beam, using a series of anti-scatter baffles just outside of the optical path, and coating all surfaces with a very non reflective material. The literature contains designs for such systems as well as the formulations of paints and surface treatments for accomplishing these goals.
Unfortunately, the above approaches are very difficult to use in a mirror folded system, such as is used for many X-ray imaging systems, including the present invention. Further, if one wants to restrict the depth of the optical system (which is the case with the present invention) by using a mirror angle of 45 degrees or less, the problems of containing the light emitted at angles that would normally not fall into the collection cone and keeping this light from reflecting back onto the diffuse phosphor surface (where it may then bounce back into the collected beam) becomes virtually impossible.
It is thus evident that improvements are needed within X-ray radioscopic imaging systems, as well as any imaging system that uses light emitted from a diffuse phosphor screen into the collection cone of an objective lens, that both: (1) increase the fraction of light from the phosphor converter screen that is collected into the collection cone of the objective lens, and (2) which reduce the effects of light emitted from the diffuse phosphor screen not captured by the lens.
The present invention addresses the above and other needs.
The present invention enhances the optical portion, or xe2x80x9cimagerxe2x80x9d, of an X-ray radiographic or similar optical imaging system by increasing the fraction of light emitted from an X-ray converter screen that is directed into the collection cone of an objective lens, while at the same time reducing the effects of light emitted from the X-ray converter screen (which comprises a diffuse phosphor screen) which leaves the screen in a direction that is not captured by the lens. That is, the invention reduces the amount of light that is permitted to scatter within the imager, and also suppresses any light that does scatter within the imager. By reducing the amount of scattered light, and by suppressing what light does scatter, the collection cone of the objective lens thus receives a greater portion of the emitted light, and the optical system is thus able to produce a brighter image having improved contrast than has heretofore been achievable.
In accordance with one aspect of the invention, the amount of light permitted to scatter within the imager is reduced by focusing more light toward the center of the collecting lens through the use of thin light directing films or structures.
In accordance with another aspect of the invention, the effects of re-scattered light within the imager are suppressed, or minimized.
In general, one of three basic ways may be used to both intensify on-axis light (focused light) captured by the lens and to reduce or suppress off-axis light (scattered light). First, a baffle-like structure or film that functions much like a venetian blind (sometimes referred to herein as a xe2x80x9cChevron structurexe2x80x9d) may be used to limit the angle of emission (and transmitted intensity) of the light that is directed to the lens. Second, the light directed to the imaging lens may be refocused with a sheet of tiny microlenses or one or more linear micro prism structures adapted to collect a large fraction of the light emitted below their collection surface area. Advantageously, such refocusing elements have a focal point very near the imaging screen""s surface (thereby allowing the light to be highly focused); or, by proper choice of orientation, such refocusing elements may actually redirect an already restricted emission to incline its center more into the collection cone and away from any other surfaces within the enclosure. Further, for that light which does scatter back from the walls of the enclosure, it may be made to strike specific reflecting surfaces rather than the diffuse surface of the screen so that the likelihood of the light being scattered into the collection cone is reduced. Third, combinations of the first and second re-scattering reduction techniques described above may be used in a correlative manner so that their combined effects add in a beneficial way to both reduce off axis light as well as intensify the on-axis light captured by the lens.
In accordance with another aspect of the invention, appropriate linear structures may be used along a single axis, providing enhanced optical properties in one dimension, or crossed linear structures may be used along two axes, providing enhanced optical properties in two dimensions.
The invention is particularly applicable in situations where the light from the conversion screen is limited. Such situations occur in low voltage, X-ray imaging systems where the light emitted per X-ray photon is weak due to the intrinsic low energy contained in the individual X-rays. Primary applications of this type include, among others, medical applications, e.g., mammography and tissue imaging. Alternatively, one also finds the same situation in industrial radiography of low-density structures such as composite materials. At the other extreme are cases in which the X-ray conversion screen (which converts X-ray energy to light), has been chosen to be of a very high density to provide good interaction efficiency but where the phosphor does not convert the energy to light with great efficiency. In either case, one of the aspects of the present invention is directed to improving the amount of light captured from the screen into an optical system and subsequent imager. The light collection may be a function of (1) the initial X-ray energy flux, (2) the probability of interaction within the screen, (3) the energy to light efficiency, or (4) the optical collection efficiency of the lens or other optical system. The described embodiment is directed particularly to improving light collection by way of the last term in the equation, i.e., the optical collection efficiency.
Since the goal of a good imaging system is to bring down all sources of noise to a level below one X-ray photon, it is important that each X-ray event produce the highest detectable light output possible. This is the primary of effect of the enhanced X-ray converter screen for radioscopic systems described herein. The additional benefit is that the internal scattering of light within the imager enclosure is significantly reduced which also benefits the image quality by extending the range of penetration into the darker portions of the image.
It is thus an object of the invention to employ light-directing films or Chevron-like structures within the optical portion of an X-ray radiographic or similar optical imaging system that provide simple masking of emission angles so as to better direct the reflected light into the collection cone.
It is another object of the invention to provide light-directing structures within the optical portion of an X-ray radiographic or similar optical imaging system that use the refractive power of an array of lenslets or linear microprisms.
It is yet another object of the invention to provide an X-ray converter screen and a method of converting X-ray radiation to visible light.
It is a further object of the present invention to provide a radiographic system employing an objective lens in which a visible light emission modification layer is superposed with an X-ray converter screen for generally focusing the diverging visible light as a restricted cone of illumination propagating outwardly from each point impinged on the screen to increase the fraction of light directed into the collection cone of the objective lens while reducing the amount of scattered visible light from the screen.
An advantage provided by the invention is that such light-directing films or structures effectively concentrate the emission angle of the normal lambertian pattern and redirect the centroid of that angular distribution toward the center of the collecting lens, thereby providing an enhanced image for the imaging system. In effect, this approach trades off an increase in brightness and reduction in off axis emission for the spatial quantification of the totality of light emitted from under each lenslet, microprism or other structure.
In a described embodiment, a radiographic system uses an X-ray converter screen for converting impinging X-ray radiation to visible light, and thus each point impinged on the screen by X-ray radiation scintillates visible light emissions diverging from the screen. An CCD camera image sensor is configured to sense the visible light from the screen. An aspheric objective lens operable with the CCD camera spatially senses visible light within a collection cone directed outwardly from the image sensor. An emission modification lens layer may be provided as a prismatic brightness enhancement film, through which the visible light emitted from the screen is transmitted is superposed with the screen and positioned in an optical path between the aspheric lens and the screen.
Briefly summarized, the present invention relates to a radiographic system and an X-ray converter screen including a substrate for converting impinging X-ray radiation to visible light, each point impinged on the substrate by X-ray radiation scintillating visible light emissions diverging from the substrate. An emission modification layer through which the visible light emitted from the substrate is transmitted generally limiting the diverging visible light to a restricted cone of illumination propagating outwardly from each point impinged on the substrate by the X-ray radiation. The invention further relates to a method of converting X-ray radiation to visible light by providing an X-ray converting screen, and then superposing the screen with a transmissive film for modifying the transmission of visible light emitted from the screen to generally limit the diverging visible light to a restricted cone of illumination propagating outwardly from each point impinged on the screen by the X-ray radiation.
From an imaging system point of view, and with particular reference to the disclosure provided in the ""774 patent, a goal of the present invention is to use the enhanced optical system herein described within a completely digital imaging system capable of recording and digitizing the individual X-ray image data, including the ability to store and retrieve that data onto a suitable storage medium, such as a hard disk of a portable computer. Such portable computer may then serve as a controller for selectively displaying the image in a way that reveals the full dynamic range and resolution of the sensor. In addition, the image captured by the system may be transmitted to remote locations (when necessary) via a modem for evaluation by experts who are not on site.
The above and other goals are met by providing a portable, self-contained, electronic radioscopic imaging system. Such system typically includes three main subsystems: (1) an X-ray source, (2) a remote X-ray sensor, or xe2x80x9cimagerxe2x80x9d, and (3) a self-contained, display and controller unit, or xe2x80x9cdisplay/control unit.xe2x80x9d The X-ray source emits X-rays at the object being investigated. The X-ray sensor or imager utilizes a scintillating screen that produces flashes of light when impinged by an X-ray in combination with either an integrating CCD camera, or an active matrix of thin film transistors and thin film sample-and-hold photodiodes, to produce an integrated signal that represents the sum of the radiation that pass through the object in a given pixel area. Advantageously, the light directing films or structures described herein, when used within the imager, produce an image exhibiting more brightness and better contrast than has heretofore been available in an imaging system of this kind. The self-contained display and control unit utilizes digital signal processing within an enhanced portable computer, including a solid-state flat panel display and associated drive circuitry, in order to display to an operator the full dynamic range and resolution of an image-capturing sensor utilized within the imager. A modem further permits the digitized image to be sent to a remote location where the exact same image can be recreated for analysis by off-site experts.
Other features of the imaging system may be the same as, or substantially similar to, those described in the ""774 Polichar et al. patent, previously incorporated herein by reference.

Design and manufacturing approach to the implementation of a microlens-array based scintillation conversion screen

Science Applications International Corporation


Disclosed is an LED lighting apparatus equipped with a high-efficiency power supply, capable of representing high power efficiency even in a low-power LED lighting apparatus by recycling a surplus voltage to charge a condenser, which supplies power to the controller, with the surplus voltage if the surplus voltage is generated from an LED acting as a load after a rectified voltage supplied to the LED has been consumed in the LED according to a design value.

1. Field of the Invention
The present invention relates to an LED lighting apparatus equipped with a high-efficiency power supply. In more particular, the present invention relates to an LED lighting apparatus equipped with a high-efficiency power supply, capable of representing high power efficiency even in a low-power LED lighting apparatus by recycling a surplus voltage to charge a condenser, which supplies power to the controller, with the surplus voltage if the surplus voltage is generated from an LED acting as a load after a rectified voltage supplied to the LED has been consumed in the LED according to a design value.
2. Description of the Related Art
An LED (light emitting diode) is an electrical/optical conversion semiconductor device to emit a light as electricity is applied thereto, and extensively used for a backlight of a display. In addition, since the electrical/optical conversion efficiency of the LED is more increased with the advance of technologies as compared with existing light bulbs and existing fluorescent lamps, the LED has been extensively used as general lighting devices. However, in the LED, since a current greatly varies even if a voltage slightly varies, the current must be accurately controlled.
As shown in FIG. 1, an LED lighting apparatus according to the related art includes an AC voltage source 910 to supply an AC voltage, a rectifier 940 to convert the AC voltage received from the AC voltage source 910 into a DC rectified voltage Vrect, first to third LED blocks 971 to 973 that act as loads and are driven by the rectified voltage, which is an output of the rectifier 940, a switch block including first to third by-pass switches SW11 to SW13 arranged in series to by-pass the currents of the LED blocks, a current source CS9 to restrict the current of the load, a controller 904 to control the switch block and a current source, a power supplying condenser C9 to supply a DC power to the controller 904, and a resistor R9, a diode D9, and a zener diode ZD9 for overvoltage protection that constitute a charging circuit to charge the power supplying condenser C9.
Accordingly, if the AC voltage source 910 starts to supply a commercial voltage, the power supplying condenser C9, which supplies a DC power to the controller, is charged with the voltage by the charging circuit, and the controller 904 controls the switch block so that LED blocks suitable for the instantaneous rectified voltage Vrect are arranged in series, and restricts an amount of a current flowing through the loads by controlling the current source.
Hereinafter, the charging circuit will be described in more detail. If the rectifier 940 starts to supply the rectified voltage Vrect, a current, which has passed through the resistor R9 and the diode D9 connected to each other in series, starts to be charged in the condenser C9 for supply DC power. Then, if the condenser C9 is charged with the current, so that a voltage Vcc across both terminals of the condenser C9 exceeds the minimum voltage (for example, DC 5V) to operate the controller 904, the controller 904 commences the operation thereof.
Meanwhile, if the DC power supplying condenser C9 is excessively charged, so that the voltage Vcc across both terminals of the DC power supplying condenser C9 reaches the maximum operating voltage (for example, DC 28V) to operate the controller 904, the zener diode ZD9 for overvoltage protection is operated to prevent the voltage of the condenser C9 from being charged up. In addition, if the rectified voltage Vrect is dropped to the voltage Vcc across both terminals of the DC power supplying condenser C9 or less, the diode D9 prevents the DC power supplying condenser C9 from being discharged through the resistor R9.
Hereinafter, the problems caused in the related art will be described.
First, the AC voltage source 910 supplies a commercial voltage of 220 Vrms. On the assumption that the maximum operating voltage of the controller 904 is DC 28V (i.e., 20 Vrms), and the current required for the controller 904 is 1 mA, the power consumed in the resistor R9 becomes 200 mW obtained by 200 Vrms×1 mA.
Accordingly, when high power is required, for example, when a 20 watt LED lamp is driven, about 1% of power is used to generate the driving power of the controller 904. In addition, when low power is required, for example, when a 4.4 watt LED lamp (220V×20 mA) is driven, about 4.5% of power is used to generate the driving power of the controller, so that power efficiency is lowered. Accordingly, the improvement is required to increase power efficiency in the low-power LED lighting apparatus.

LED lighting apparatus equipped with high-efficiency power supply


A baton structure having first and second cylindrical housings arranged for securement relative to one another are provided, wherein each of the first and second housings include housing tubes and rods arranged for telescoping extension and locking relative to each of the housings, with each of the rods having a resilient tip for use as a friction tip to promote displacement along a skating surface by an individual. The first housing includes a reflective mirror structure for viewing traffic conditions rearwardly of an individual, with the second housing having a fluid dispenser to dispense a defensive fluid such as (MACE) therefrom.

1. Field of the Invention
The field of invention relates to pole structure, and more particularly pertains to a new and improved skate baton apparatus to permit enhanced ease of transport along an underlying skating surface.
2. Description of the Prior Art
Various manipulation pole structure such as ski poles indicated in U.S. Pat. Nos. 4,775,168; 4,620,723; and 4,955,969 as examples are indicated in the prior art to permit projecting of individuals along an underlying surface, wherein the instant invention attempts to overcome deficiencies of the prior art by providing for a break-down baton structure arranged for ease of assembly and disassembly to provide for a plurality of batons having telescoping friction tips and in this respect, the present invention substantially fulfills this need.


A disk drive motor having a low profile construction and a gas-lubricated deflecting pad support usable in the disk drive motor and elsewhere includes a cup-shaped rotor having an integral cylindrical portion extending from the base of the cup; the cylindrical extension may be a shaft or a large hollow extension which encloses the stator windings. The stator can be conventional or can have a closed end and/or a cup-like portion to simplify construction and eliminate the need for a seal. A support mounted on the stator or the rotor supports the rotor for rotation relative to the stator. The support can be a deflecting pad support such as a deflecting pad hydrodynamic bearing or the plane or gas-lubricated deflecting pad support disclosed herein.. The gas-lubricated deflecting pad support member includes bearing pads and a support structure which supports the bearings for strictly radial movement. A contoured surface is formed on the pad surfaces or a support surface opposing the pad surfaces or both. Relative rotation between the pad surfaces and the support surface results in the development of a pressurized gas film between the support surface and the pad surface.

This invention relates, in part, to a motor for rotating a magnetic disk. In particular, it relates to a motor which is used for an application in which magnetic disks, each formed with a magnetic layer on a metal disk are driven by the motor, and data is recorded on and reproduced from the magnetic disk by magnetic heads disposed near the upper and lower surfaces of each magnetic disk. Such motors are commonly referred to as disk drive motors.
The increasing use of rotating magnetic disks as a computer memory medium has created a demand for small, high speed drives which accurately rotate and position magnetic disks memories. External rotor type motors having a permanent magnetic rotor which surrounds a stator, such as a multiple pole stator, have been used in such drives. One such construction is shown in U.S. Pat. No. 4,599,664 to Schok. The stator typically has a one-phase winding which produces an alternating field and an auxiliary reluctance moment which, in cooperation with the electromagnetic torque, produces a total torque of high constancy. The rotor shaft is mounted within the stator by a ball bearing structure, with the rotor secured to the outer end of the motor shaft and defining a cantilevered bearing support. The disk drive is secured to the opposite end of the motor shaft.
Disk drives require structures for supporting the cantilevered mounted rotor which provide accurate and long-life support. Various sleeve and rolling element (e.g., ball) bearing structures have been suggested for use in permanent magnet motors for disk drives.
In one ball-bearing unit, described in the background of U.S. Pat. No. 4,762,250 to Seitz, a pair of axially spaced high precision rotary ball-bearings are secured within a machined hub of the stator structure. The outer race of each bearing is fitted within the hub. The outer race of a first bearing is bonded within the hub. The second bearing is held in the hub during assembly by a special O-ring member located within an annular recess in the hub. The inner races of the bearings are fitted onto the motor shaft and generally into abutting relation with a locating shoulder on the shaft and an outer hub member on the outer end of the shaft. A steel snap-ring or an integral spacer is interposed within a machined recess in the hub between the two bearings. Suitable flat spring washers are interposed between the snap-ring and the respective opposed outer bearings of the two space-bearings to resiliently load the bearings and hold them in position with the desired accuracy and support.
The Seitz patent also discloses a cup-shaped rotor which overlies the stator and has a rotor shaft journalled in the hub by spaced sealed precision bearings.
Although rolling element bearings such as ball bearings have been and are presently widely used in commercially available motors, their use presents a number of problems. For example, ball bearings are subject to relatively fast wear and rapid damage, especially if the environment in which they are located becomes contaminated. This is, of course, true for any support structure which relies on rolling or other solid contact between the rotating and stationary members. Additionally, ball bearings are bulky and increase both the radial and verticle dimension of the disk drive significantly. For these reasons, ball bearings adversely affect both the cost and reliability of disk drives. Thus, there remains a need to improve the operating characteristics of the rotor support structure to minimize the cost.
Of course, there are many known alternatives to rolling element (ball, roller and needle) bearings. Among these are pivoting element bearings and hydrodynamic bearings. Also, the present inventor has developed a deflecting pad hydrodynamic bearing which includes a plurality of bearing pads and a support structure which supports the bearing pads for deflection in a manner which optimizes hydrodynamic wedge formation. Despite recent advances in these alternative bearing technologies, most notably the present inventor's developments in the field of hydrodynamic bearings, these technologies have not been widely used in disk drives. To some extent this may be the result of a failure to recognize the applicability of other forms of bearings to disk drives or the recent nature of improvements in bearing technology.
Another known bearing is the so-called gas-lubricated bearing. Such bearings are made by forming (typically by etching) a contoured surface onto the surface of one or both of the rotating shaft and the stationary shaft support. For manufacturing convenience, the contour is usually formed on only one of the surfaces and one of the two opposed surfaces is left smooth. A precise clearance between the support surface and the shaft, at least one of which has a contoured surface is maintained, such that, as the shaft begins to rotate, gas flowing across the contoured surface becomes turbulent and is pressurized to the extent necessary to support the shaft. If the tolerances are carefully maintained so that the bearing operates as designed, the shaft and bearing do not make contact; instead, the shaft is supported on a cushion of pressurized air. Such gas-lubricated bearing constructions can be applied to both radial bearings and thrust bearings. Further, various contoured shapes may be used including taper, taper-flat, step, pocket, spiral groove and herringbone contours. At least for thrust bearings, it is believed that a spiral groove contour is probably the best.
One of the major drawbacks of conventional gas-lubricated bearings, particularly with respect to radial bearings, is the small manufacturing tolerances required to maintain tight clearances. Since gas-lubricated bearings are typically used in small light load applications and the depth of the contour can be in the range of 1/10,000 of an inch, such spacing between the shaft and support member must be very small. In practice, it has proven difficult to economically manufacture to these close tolerances. Thus, despite the advantages they offer, gas-lubricated bearings have also not yet found wide acceptance as a substitute for rolling element and other types of bearings.
A similar drawback occurs with another known bearing commonly referred to as a plane or oilite bearing. This bearing is simply a smooth sleeve formed of a porous metal such as, for example, bronze. The porous metal is loaded with an oil or graphite lubricant. The support surface of the element moving with respect to the plane bearing simply slides on the oil or graphite lubricated surface of the plane bearing. However, in order to achieve uniform wear and to obtain accurate shaft positioning, the bearing must be manufactured to extremely close tolerances. Consequently, this type of bearing is not widely used in disk drives.
As suggested above, alternative bearing constructions have not yet been incorporated into disk drives in a commercially successful way. Thus, despite the recognized drawbacks of rolling element bearings, they are still prevalent in the disk drive industry.
Another trend within the disk drive field has been toward low-profile disk drives; this is particularly true in the lap-top computer field. Numerous attempts have been made to decrease the profile (verticle height) of disk drives without affecting performance. One example of such an attempt is that disclosed in U.S. Pat. No. 4,658,312 issued to Elsasser, et al. Constructions such as this typically employ ball-bearings and a separate shaft and rotor; these features limit the extent to which vertical height can be decreased because, for example, the top of the rotor housing must be thick enough to allow connection with the separate shaft.
Thus, there remains a need for a low-profile disk drive which is reliable, inexpensive and light weight. There is also a need for means, other than ball-bearings for supporting the shaft of a low-profile disk drive construction. Finally, there is a need for a gas-lubricated bearing which can be economically manufactured, i.e., does not have to be manufactured to close tolerances.


A semiconductor light emitting device which has a wavelength converting part on a semiconductor film and can eliminate unevenness in emission color without a reduction in light output. The semiconductor film includes a light emitting layer. The support substrate is bonded to the semiconductor film via a light-reflecting layer and has a support surface supporting the semiconductor film and edges located further out than the side surfaces of the semiconductor film. The light-shielding part covers the side surfaces of the semiconductor film and part of the support surface around the semiconductor film in plan view. The wavelength converting part contains a fluorescent substance and is provided over the support substrate to bury the semiconductor film and the light-shielding part therein. The wavelength converting part has a curved surface shape in which its thickness increases when going from the edges toward the center of the semiconductor film.

1. Field of the Invention
The present invention relates to a semiconductor light emitting device including a light emitting element such as an LED (light emitting diode).
2. Description of the Related Art
Light emitting diodes (hereinafter called LEDs) are used in car tail lamps, various displays, the backlights of mobile devices such as mobile phones, and so on. The demand for LEDs for car headlights, the backlights of liquid crystal displays, and general lighting is expected to increase greatly from now on. For car headlights and general lighting, white light is desirable. The color of light of the LED is determined by the magnitude of the band gap of the semiconductor layer and is intrinsic to the semiconductor crystal used. Hence, the color of light of the LED is a single color such as red, green, or blue. The methods for obtaining white light using LEDs of this light-emitting characteristic are as follows.
The first method is to arrange a red LED, a green LED, and a blue LED and make them emit light at the same time. However, in the case of this method, color unevenness may be likely to occur depending on the viewing direction because of the strong directivity characteristic of LEDs. Further, because the rate at which the LED varies with an environmental factor such as temperature is different between the LEDs of respective different colors and the speed at which the LED deteriorates is also different, it is difficult to maintain the white color.
The second method is to combine a blue LED and a yellow fluorescent substance, thereby obtaining white light. The fluorescent substance absorbs blue light to emit yellow light of a longer wavelength. Part of blue light emitted from the blue LED is converted by the fluorescent substance into yellow light, and the other part passes through a fluorescent substance layer including the fluorescent substance with maintaining its blue color. The yellow light emitted from the fluorescent substance and the blue light are mixed to produce white light. According to this method, white light can be obtained with use of a single blue LED chip, and hence the device is simple in configuration and can be manufactured at lower cost than by the above first method wherein LEDs of emission colors of RGB are arranged.

Semiconductor light emitting device and manufacturing method of the same


The present disclosure discloses a pixel unit circuit and an OLED display apparatus. The pixel unit circuit comprises a first sub-circuit module, a second sub-circuit module, a first capacitor and OLED. An input of the first sub-circuit module is connected to a data line; another input of the first sub-circuit module is connected to an output of the second sub-circuit module and a first terminal of the OLED; an output of the first sub-circuit module is connected to an input/output of the second sub-circuit module via the first capacitor; a voltage difference between positive power supply and negative power supply of a backboard is applied between an input of the second sub-circuit module and a second terminal of the OLED. The pixel unit circuit can compensate the aging of OLED devices, the non-uniformity of threshold voltage of TFT driving transistors, and IR Drop of the power supply of the backboard.

As a current type light emitting device, OLED is increasingly applied to a high performance display. Conventional Passive Matrix OLED (PMOLED) requires shorter single pixel driving time for display, and thus needs increasing a transient current, rendering the increase of the power consumption; meanwhile, the employment of large current causes voltage drop of the Indium Tin Oxide (ITO) line to decrease too much, rendering the operation voltage of OLED too high and in turn the efficiency of OLED lower. An Active Matrix OLED (AMOLED) inputs OLED current via switching transistors by progressive scanning for display, which can solve the above problems very well.
Firstly, as an example, in the design for the backboard of AMOLED, a low temperature poly-Si Thin Film Transistor (LTPS TFT) is mostly adopted in AMOLED to constitute a pixel circuit for providing the corresponding current for the AMOLED device. As compared to the conventional amorphous-si TFT, LTPS TFT has a higher mobility and a more stable characteristics, and thus is more suitable to be used in an AMOLED display. However, due to the limitation of the crystallization process, LTPS TFTs, which are manufactured on a large glass substrate, have non-uniformity in electrical parameters such as threshold voltage, mobility, etc, and such non-uniformity may result in variances of current and luminance of OLED which can be perceived by human eyes, i.e., Mura phenomenon.
Secondly, in a large size display application, there is a certain resistance in the power cord of the backboard, and all of pixels are provide with driving current by the positive power supply (ARVDD) of the backboard, so the supply voltage in the area near the location of the power supply ARVDD is higher than that in the area located far from the location of the power supply ARVDD, and such phenomenon is called IR Drop. As the current of OLED depends on the voltage of ARVDD, IR Drop also results in variances of current in different areas, and Mura phenomenon in turn occurs in display.
Thirdly, there is also the non-uniformity in electrical parameters due to the non-evenness of the film thickness generated when OLED device is evaporated. FIG. 1 illustrates a schematic relationship between the luminance and the operation time of OLED and relationship between the threshold voltage and the operation time of OLED, wherein  denotes luminance of OLED and  denotes threshold voltage of OLED. As shown in FIG. 1, after OLED operates for a long time, the deterioration of the internal electrical performance of OLED results in the rise of the threshold voltage VOLED—0, and thus luminance efficiency decreases and luminance lowers.
It becomes an important issue that how to compensate the aging of the OLED device, since the aging of OLED causes Image Sticking to present in the area which displays a fixed picture for long time, affecting the display effect.
FIG. 2 illustrates a schematic relationship between luminance loss and threshold voltage of OLED, and FIG. 3 illustrates a schematic relationship between luminance and current density of OLED. As shown in FIG. 3, "" denotes the relationship between the luminance of red light OLED and the current density, "" denotes the relationship between the luminance of green light OLED and the current density, and "" denotes the relationship between the luminance of blue light OLED and the current density. As illustrated in FIG. 2 and FIG. 3, a substantially linear relationship is represented between the rise of threshold voltage and the luminance loss of OLED, and a linear relationship is also represented between the current density and the luminance of OLED. Therefore, when compensating the aging of OLED, the luminance loss can be compensated by increasing the driving current of OLED linearly as the threshold voltage of OLED increases.
AMOLED can be classed into three types in driving mode, i.e., digital driving mode, current driving mode, and voltage driving mode. The digital driving mode achieves a grey level by controlling driving time via TFT as a switch without compensating non-uniformity. Nevertheless, the operation frequency will be multiplied as the size of a display increases, which results in a high power consumption and to some extent reaches the physical limit of design. Therefore, the digital driving mode is not suitable for a large size display. The current driving mode achieves a grey level by providing different current to the driving transistors directly, which can compensate the non-uniformity of TFT and IR Drop. However, when a signal of a low grey level is written, the time for writing is prolonged too much since it is a small current to charge the large parasitic capacitance on a data line. Such a problem is more serious in a large size display and is difficult to be overcome. The voltage driving mode is similar to the conventional AMLCD driving mode, wherein a voltage signal representing a grey level is provided by a driving IC, and the voltage signal is converted to a current signal of a driving transistor inside a pixel circuit, and then the current signal is used to drive OLED to achieve luminance grey level. The voltage driving mode has such advantages as high driving speed and simplicity of implementation, and thus is suitable for driving a large size panel and is widely used in the art. However, extra devices such as TFTs and capacitors to compensate non-uniformity of TFT and IR Drop will be required.
FIG. 4 is a schematic diagram showing structure of a conventional pixel unit circuit of voltage driving type which comprises 2 TFT transistors, 1 capacitor and an OLED. A switching transistor T2 transmits a data voltage from a data line to a gate of a driving transistor T1, the driving transistor T1 converts the data voltage to a corresponding current and supplies the same to the OLED. In normal operation, the driving transistor T1 should operate in a saturation area, and should provide a constant current during a scanning time for one line. The current can be expressed as follows:
      I    OLED    =            1      2                          μ        P            ·              C        ox            ·              W        L            ·                        (                                    V              Data                        -            ARVDD            -                          V              th                                )                2
wherein μP is the carrier mobility, COX is the capacitance of the oxide layer of the gate, W/L is the width/length ratio of the transistor, VData is the data voltage, ARVDD is the power supply voltage of AMOLED backboard which is shared by all pixel units, and Vth is the threshold voltage of the driving transistor. It can be known that if the threshold voltages Vth are different from one pixel unit to another, then there are variances between the currents. Moreover, even if a constant current is provided to an OLED device, the emitting luminance of OLED decreases as the aging of the OLED device.
At present, there are a variety of structures of pixel unit for compensating the non-uniformity of Vth and IR drop. However, some structures of pixel unit can compensate the non-uniformity of Vth of the driving transistor, but can not compensate IR Drop and the luminance loss due to the aging of OLED; some structures of pixel unit can compensate the non-uniformity of Vth of the driving transistor and IR Drop, but can not compensate the luminance loss due to the aging of OLED; some structures of pixel unit can compensate the non-uniformity of Vth of the driving transistor, IR Drop and the affect of the aging of OLED, but are not applicable to a large size panel since their structures belong to the current driving type; and some structures of pixel unit can compensate the affect of the aging of OLED, but can not compensate the non-uniformity of Vth and IR Drop. Therefore, it is impossible for the pixel circuit presented in the prior art to effectively compensate the non-uniformity of the threshold voltage Vth of TFT driving transistor, IR Drop of power supply voltage of backboard and the affect of the aging of OLED while applicable to a large size panel.

Pixel unit circuit and OLED display apparatus


Fluid injection tools for use in a wellbore can be configured on-site prior to run-in and can be opened or closed on demand when positioned in the well. A fluid injection tool can be used to provide steam to a wellbore annulus during a steam assisted gravity drainage procedure. Nozzles in the tool through which the steam escapes can be individually plugged to enable fine-tuning of steam output to match a desired steam output for that particular tool's location within the wellbore. A sliding side door can be actuated, such as by a shifting tool inserted within the inner diameter of the fluid injection tool, to enable or disable steam output from the fluid injection tool.

In oilfield operations, it can often be useful to control the passage of fluid between the inside of a wellbore tubular and an annulus between the tubular and the wellbore or casing. During steam assisted gravity drainage (SAGD) procedures, high-pressure, high-temperature steam can be injected into an upper wellbore to heat the surrounding formation, reducing the viscosity of heavy oil and bitumen in the formation, allowing the oil and bitumen to drain into a lower wellbore for production.
When a SAGD wellbore is prepared, multiple steam release nodes can be positioned along the length of the generally horizontal upper wellbore. In order to maximize the efficiency of the SAGD process, it can be desirable to adjust the amount of steam that is to be released at each node. Current SAGD nodes must be custom made to order after receipt of specifications for the particular SAGD wellbore. Custom made SAGD nodes can take a long time to prepare and ship and have extremely limited potential for re-use. Custom made SAGD nodes cannot be adjusted after manufacture or onsite in the event of changes in the SAGD wellbore specifications requiring more or less steam release from a particular node.


An ice dispenser for a domestic refrigerator includes a lever having a housing with a passageway defined therein and a flapper door configured to pivot between a closed position in which ice is prevented from advancing into the passageway and an open position in which ice is permitted to advance into the passageway. A linkage is coupled to the lever and the flapper door such that movement of the lever causes the flapper door to move from the closed position to the open position.

A domestic refrigerator is a device used to store food items in a home at preset temperatures. A domestic refrigerator typically includes one or more temperature-controlled compartments into which food items may be placed to preserve the food items for later consumption. A domestic refrigerator also typically includes a door that permits user access to the temperature-controlled compartment, and many domestic refrigerators also include a dispenser in the door that is operable to dispense water and/or ice.

Domestic refrigerator including an ice dispenser


A dual color matching feedback control method, system and processor-readable medium for hiding an infrared marking in a wide range of customer selectable colors. The approach includes an inline spectrophotometer sensor to measure at least two color mixtures and a matching color feedback control unit adjusts the two mixtures to match each other in color appearance. A customized color can be selected from a smaller gamut of darker color by a customer and a sufficient difference in a black toner (k toner) between the two color mixtures can be maintained to provide sufficient contrast for the infrared detection. An initial match can be provided by incorporating a color model that is similar to a predicted color mixture. The two colors can then be rendered and adjusted for better match prior to rendering the hidden mark. Such an approach adjusts an amount of other toners so that the color difference between the hidden mark colorant and a surrounding colorant is minimized and a presence of the hidden mark is less detectable to the observer under a standard condition.

Hidden marks such as, for example, barcodes, text, security marks and other information-rich symbols containing information can be incorporated into a particular graphical design along with a customized color that compliments or matches the graphical design selected by a user (e.g., a customer). Barcodes, for example, can be utilized to embed data in a printed format in order to provide automated identification and tracking capabilities in a number of applications. A color barcode may record more information than a black and white barcode by multi-valued recording. Production printing applications, such as, for example, photo book printing, typically hide the barcodes at the bottom right hand corner of a back cover.
Conventional approaches for matching two colors for hiding infrared markings involve limiting the user to select from a palette of a limited number of qualified match colors. Additionally, maintaining a sufficiently large difference in a black toner (k toner) assures an adequate contrast for discerning the hidden marks. The contrast can be detected under an infrared illumination (e.g., using an infrared barcode reader) as the colorant with blacker toner absorbs more infrared and appears darker.
Unfortunately, different amounts of black toner can create color differences that may be noticeable under a standard viewing condition. Furthermore, hiding the marks or degree that the observer can visualize the hidden mark is highly dependent on matching the two colors. The marks become easier to visualize if a color rendering device drifts or does not provide consistency in color matching.
Based on the foregoing, it is believed that a need exists for an improved dual color matching feedback control system and method for hiding an infrared marking. A need also exists for maintaining sufficient difference in a black toner between color mixtures to provide sufficient contrast for the infrared detection, as will be described in greater detail herein.

Dual color matching feedback control method and system for hiding infrared markings and other information


A microminiature vacuum tube includes a single crystal semiconductor substrate having opposed first and second surfaces; a V-shaped groove extending into the substrate from the first surface; an aperture extending into the substrate from the second surface and intersecting the V-shaped groove; an electron-emitting material disposed on the substrate in the V-shaped groove, extending into the aperture, and having a sharp edge in the aperture; and a first insulating layer, a metal gate layer, a second insulating layer, and a metal anode layer successively disposed on the second surface of the substrate adjacent the aperture and spaced from the sharp edge of the electron-emitting material.

The microminiature vacuum tube utilizes electrons traveling in vacuum, and unlike the general vacuum tubes, it is formed on a semiconductor substrate. Therefore, a cathode of electric field emission type is used which emits electrons by means of an electric field. To emit electrons in such a cathode, the shape of the electron emitting end of the cathode is required to be as sharp as possible.
A description is given of an example of the conventional method of manufacturing a microminiature vacuum tube with reference to FIGS. 3(a)-3(e).
First, as shown in FIG. 3(a), a mask material is formed on the entire surface of a monocrystalline substrate 1, and the mask material on portions other than a portion 2 to become a cathode is removed by photolithography.
Next, as shown in FIG. 3(b), the substrate 1 is etched by dry etching such as RIE (reactive ion etching) using the mask material 2 as a mask. Furthermore, the substrate i is etched in the lateral direction and obliquely by anisotropic wet etching using an etchant such as potassium hydroxide, and a protrusion is formed which has an acute-angled tip 9 which becomes a cathode later (FIG. 3(c)).
Next, an insulating material 5 for protecting the tip shape of the cathode is formed on the entire surface of the substrate and a metal film 68 is formed thereon, and thereafter resist patterns 11 are produced thereon by photolithography (FIG. 3(d)). The metal film 68 and the insulating material 5 are etched by RIE or the like using resist patterns 11 as a mask and a gate 6 and an anode 8 are at periphery of the cathode formed on the substrate 1, thereby completing a device (FIG. 3(e)).
When this device is used, the cathode voltage Vc is made the ground level by grounding the substrate 1 as shown in FIG. 4, and a voltage V.sub.A of 100 to 500 V is applied to the anode 8. Electrons emitted from the cathode 9 into vacuum by means of electric field emission are collected by the anode 8. Meanwhile, the quantity of electrons flowing from the cathode 9 to the anode 8 is controlled by applying a voltage of several tens of volts to the gate 6 as a gate voltage V.sub.G.
In the conventional microminiature vacuum tube manufactured by the method as described above, etching in the lateral direction is utilized to form the cathode, therefore the control of timing for ending etching when the tip shape of the cathode becomes acute-angled is very difficult. Particularly, in fabricating a plurality of cathodes on the substrate, this control is further difficult. Actually, as shown in FIG. 5, a cathode 12b which has not been etched fully, a cathode 12c which has been etched excessively and the like are formed besides a cathode 12a having a desired shape. Thus, variations occur in the shape of the cathode.
Also, the area of adhesion between the portion to become the cathode on the surface of the substrate 1 and the mask material 2 becomes smaller as the etching progresses, and therefore the adhesion force between the both is weakened. This results in peeling of the mask material and the etched shape varies. Therefore it is difficult to obtain a uniform etched shape.
Further, the tip of the cathode is required to be protected when the gate and the anode are formed, and in the conventional example, the tip is protected by an insulator film such as SiO.sub.2. However, the tip part of the cathode is actually exposed to an etching gas immediately before the gate 6 and the anode 8 are formed, and for this reason, the tip part of the cathode is damaged and it is difficult to maintain the original sharp tip shape.
As described above, in the conventional manufacturing method, the controllability and the reproducibility of the etching process for forming the cathode are worse, and further the tip part of the cathode is damaged in the stage of forming the gate and the anode, incurring non-uniformity in the device characteristics.


The present invention presents a method for detecting an endpoint of an etch process for etching a substrate in plasma processing system (1) comprising: etching the substrate; measuring at least one endpoint signal; generating at least one filtered endpoint signal by filtering the at least one endpoint signal, wherein the filtering comprises applying a Savitsky Golay filter (12) to the at least one endpoint signal; and determining (14) an endpoint of the etch process from the at least one filtered endpoint signal.

1. Field of the Invention
The present invention relates to a method and apparatus for plasma processing a substrate, and more particularly to an improved method for determining an endpoint during a plasma etch process.
2. Discussion of the Background
Typically, during semiconductor processing, a (dry) plasma etch process is utilized to remove or etch material along fine lines or within vias or contacts patterned on a silicon substrate. The plasma etch process generally involves positioning a semiconductor substrate with an overlying patterned, protective layer, for example a photoresist layer, into a processing chamber. Once the substrate is positioned within the chamber, an ionizable, dissociative gas mixture is introduced within the chamber at a pre-specified flow rate, while a vacuum pump is throttled to achieve an ambient process pressure. Thereafter, a plasma is formed when a fraction of the gas species present are ionized by electrons heated via the transfer of radio frequency (RF) power either inductively or capacitively, or microwave power using, for example, electron cyclotron resonance (ECR). Moreover, the heated electrons serve to dissociate some species of the ambient gas species and create reactant specie(s) suitable for the exposed surface etch chemistry.
Once the plasma is formed, selected surfaces of the substrate are etched by the plasma. The process is adjusted to achieve optimal conditions, including an appropriate concentration of desirable reactant and ion populations to etch various features (e.g., trenches, vias, contacts, etc.) in the selected regions of substrate. Such substrate materials where etching is required include silicon dioxide (SiO2), low-k dielectric materials, poly-silicon, and silicon nitride. As the feature size shrinks and the number and complexity of the etch process steps used during integrated circuit (IC) fabrication escalate, the requirements for tight process control become more stringent.
Consequently, real time monitoring and control of such processes becomes increasingly important in the manufacture of semiconductor ICs. For example, one such monitoring and control diagnostic necessary for the timely completion of an etch step or process is endpoint detection. Endpoint detection refers to the control of an etch step and, in particular, to the detection of the feature etch completion or the instant in time when the etch front reaches the etch stop layer. If the etch process endpoint is improperly detected, then severe under-cutting of the feature may occur due to over-etching or partially complete features may result due to under-etching. As a result, poor endpoint detection could lead to devices of poor quality that are subject to increased risk of failure. Therefore, the accurate and precise completion of an etch process is an important area for concern during the manufacturing process.
One approach used for endpoint detection is to monitor the emission intensity of light at a pre-specified wavelength in time using optical emission spectroscopy (OES). Such a method might identify a wavelength corresponding to a chemical species present in the etch process that shows a pronounced transition at the etch process endpoint. Subsequently, a resultant signal is analyzed to detect distinct variations in the emission intensity, and the analysis of the resulting signal is then used to correlate with the completion of an etch process. Typically, the species selected corresponds to a reactive species or a volatile etch product. For example, the selected wavelength may correspond to CO* emission when etching SiO2 and polymer films, N2* or CN* emission when etching nitride films, SiF* emission when etching poly-silicon and AlCl* emission when etching aluminum.
In addition to the approach of monitoring the emission intensity at a single wavelength as described above, another approach is to monitor the light intensity at two wavelengths and record the ratio (or some mathematical manipulation thereof) of the two intensities. For instance, one wavelength is chosen for a specie whose concentration decays at an endpoint and a second wavelength is chosen for a specie whose concentration increases at the endpoint. Therefore, the ratio gives improved signal to noise.

Method and apparatus for detecting endpoint


A recording material detection apparatus having a detecting device configured to detect a surface state of a recording material on the basis of reflected light from a surface of the recording material includes a reference surface to be irradiated with light from a light source, the detecting device includes a light-shielding portion configured to control conditions for detecting information relating to the surface state of the recording material on the basis of the reflected surface from the reference surface, and cover a portion of the reference panel other than the reference surface so as to prevent the light from the light source from being reflected from the portion of the reference panel other than the reference surface and being received by the light-receiving unit.

1. Field of the Invention
The present invention relates to a recording material detection apparatus configured to detect a surface state of a recording material by irradiating the recording material with light and an image forming apparatus having such a recording material detection apparatus.
2. Description of the Related Art
Image forming apparatuses such as copying machines or laser beam printers are configured to transfer an developer image(toner image) visualized by a developing device on a recording material under predetermined conditions (for example, transfer biases and recording material conveyance speeds at the time of transfer). Then, by heating and pressurizing the recording medium having the developer image transferred thereon under predetermined fixing conditions (for example, fixing temperatures and recording material conveyance speeds at the time of fixing), the developer image is fixed to the recording material.
There is an image forming apparatus including a recording material detecting unit configured to irradiate a recording material with light from a light source and detect a surface state of the recording medium, and configured to determine the types of recording materials on the basis of the result of detection of the recording material detecting unit and control the transferring conditions and fixing conditions.
Such a recording material detecting unit is capable of detecting the recording material stably by controlling the conditions of detection of the recording materials via an adjustment for achieving irradiation with a stable amount of the light from the light source and a shading correction for correcting unevenness of amount of light on the surface of the recording material. More specifically, the amount-of-light adjustment of the light source and the shading correction are enabled by irradiating a reference panel (white reference) with the light from the light source and detecting reflected light therefrom.
Now, Japanese Patent Laid-Open No. 1-099187 discloses a configuration of a reference panel in which the reference panel is movably arranged on the side of a light-receiving unit with respect to the surface of the recording material (in a unit) and is moved to a reading position when needed in order to avoid the dirt or scratches on the reference panel due to the recording materials being conveyed or dust existing in the periphery thereof.
However, with the reference panel having a movable configuration, the mechanism becomes complicated correspondingly, and an increase in the size of the apparatus and a cost increase are resulted.

Recording material detection apparatus and image forming apparatus


There is provided a holding apparatus which is capable of rotatably holding, while cooling to a cryogenic temperature, a to-be-processed object in a vacuum chamber. A holding apparatus for rotatably holding, while cooling, a to-be-processed object in a vacuum chamber Vc, has a stage on which the to-be-processed object is placed, a rotary drive device for rotatably supporting the stage, and a cooling device for cooling the stage. Provided that a stage surface side on which the to-be-processed object is placed is defined as an upside, the rotary drive device has: a tubular rotary shaft body which is mounted on a wall surface of the vacuum chamber, in a penetrating manner, through a first vacuum seal; a connection member for connecting an upper end part of the rotary shaft body and a lower surface of the stage in a manner to define a space below the stage; and a driving motor for driving to rotate the rotary shaft body.

In case various kinds of processing such as film forming processing, etching processing, and the like is performed on a to-be-processed object such as silicon wafer, glass substrate, and the like in a vacuum chamber in vacuum atmosphere, it has conventionally been known to perform such processing in a state in which the to-be-processed object is electrostatically attracted by an electrostatic chuck. Here, in performing the processing on the to-be-processed object, there are cases where the to-be-processed object is maintained at a predetermined temperature or the to-be-processed object is maintained at a predetermined temperature which is lower than the room temperature. Then, it is known: to provide a base for supporting a chuck plate which constitutes an electrostatic chuck with a water flow pipe; during processing, to cause cooling water to circulate through this water flow pipe by a cooling water circulation apparatus to thereby cool the base; in this manner to cool the chuck plate and, consequently, the to-be-processed object (see, for example, Patent Document 1).
On the other hand, as a predetermined processing, in case film forming processing is performed by, e.g., sputtering a sputtering target, for the purpose, e.g., of increasing the in-plane uniformity of film thickness distribution or of forming a film on a substrate having a projection/depression shape, it is also known to connect a rotary shaft of a driving motor to a stage on which the to-be-processed object is placed in position. During processing, the stage and consequently the to-be-processed object is processed while rotating it at a predetermined speed (see, for example, Patent Document 2). By the way, in the art described in Patent Document 2, the stage is provided with an electrode for the electrostatic chuck for the to-be-processed object and with a jacket for circulating water. It is thus so arranged that the to-be-processed object is held in a manner to be rotatable and is also capable of being cooled to a predetermined temperature.
However, in each of the methods of the above-mentioned conventional examples in which a liquid such as cooling water and the like is circulated inside the stage as a coolant, despite an attempt to cool the to-be-processed object to a temperature below room temperature, there was a limit in that the to-be-processed object could be cooled down to a temperature of at most about −30° C. In addition, during the processing, should the coolant leak from the stage that is driven for rotation into the vacuum chamber in vacuum atmosphere, not only is the normal processing impaired, but also is the possibility of the processing apparatus itself be damaged. Therefore, it is necessary to employ a complete watertight construction, this bringing about a complication and higher cost of the apparatus.


A capacitor assembly is configured for use with an implantable medical device (IMD. The capacitor assembly may include a stack assembly having at least one anode stack between outer cathodes, and a housing having a case secured to a lid. The case and the lid define an internal chamber that retains the stack assembly. One of the case or the lid comprises a folded double wall connected to a drawn end. A recessed area is defined between the folded double wall and the drawn end. A linear edge of the other of the case and the lid is retained within the recessed area.

Embodiments generally relate to a charge storage assembly, and, more particularly, to a system and method for forming a charge storage assembly that may be used with a medical device.
Numerous medical devices exist today, including but not limited to electrocardiographs ("ECGs"), electroencephalographs ("EEGs"), squid magnetometers, implantable pacemakers, implantable cardioverter-defibrillators ("ICDs"), neurostimulators, electrophysiology ("EP") mapping and radio frequency ("RF") ablation systems, and the like (hereafter generally "implantable medical devices" or "IMDs"). IMDs commonly employ one or more leads with electrodes that either receive or deliver voltage, current or other electromagnetic pulses (generally "energy") from or to an organ or tissue (collectively hereafter "tissue") for diagnostic or therapeutic purposes.
Certain types of IMDs include internal charge storage members, such as one or more capacitors. The charge storage members may be connected to a switch circuit or network also referred to as an H-bridge. Conventional high voltage H-bridges include a network of transistors that are controlled to open and close in different combinations to deliver stored energy from the charge storage members to a patient through the electrodes.
Typically, a capacitor of an IMD includes a stack assembly having anodes and cathodes secured within a housing. The housing may include a case and a lid. After the stack assembly is secured within the case, the lid is positioned over the case. The lid and the case are then secured together, such as through welding at seams between the lid and the case.
Typically, the outer, exposed edges of the case are inwardly-offset toward an interior chamber of the case. The offset forms a recessed area about the outer edges that receives an outer edge of the lid. The lid and the case are then typically laser-welded proximate an interface between the lid and the case.
However, the inward offset of the case occupies space within the case. Accordingly, the case typically needs to be large enough to accommodate the stack assembly. Yet, with IMDs becoming smaller, internal space within the IMDs may be at a premium. The inward offset of the case into the internal chamber of the case may cause the capacitor to be too large for some applications.

System and method for forming a charge storage assembly


Provided are a prism apparatus applied to a periscope lens module and a periscope lens module. The prism apparatus includes a bearing frame, a supporting member, a prism installed, shape memory alloy wires connected between the supporting member and the bearing frame and configured to drive the supporting member to rotate with respect to the bearing frame, and a restoring device connected between the supporting member and the bearing frame and configured to restore the supporting member. In the present invention, the shape memory alloy wires are used to drive the supporting member and the prism, such that the prism can automatically correct the angle, thereby improving the imaging quality. Moreover, the original electromagnetic drive is replaced with the shape memory alloy wires, which reduces a manufacturing cost of the prism apparatus applied to the periscope lens module, thereby achieving a mass production of the periscope lens module.

Portable terminals, such as smartphones and tablet computers, are equipped with high-performance lens modules nowadays. The high-performance lens modules generally have an automatic anti-shake function. In the prior art, an electromagnetic drive device is usually employed to exert the automatic anti-shake function. The electromagnetic drive device includes a magnet and a coil, and the coil is energized to control the rotation of the prism to correct an angle of the prism. However, the electromagnetic drive devices are susceptible to interference from external electromagnetic fields, and the used magnets result in an increase in the overall weight and cost of the lens module.
Thus, it is necessary to provide a new lens module for solving the above problems.

Prism apparatus applied to periscope lens module and periscope lens module