In a focus detecting device of the type in which light fluxes passing through two areas obtained by dividing a pupil of an image forming lens are received by a sensor to detect a phase difference, pixels of the sensor are disposed in such a manner that the sensor has the light-receiving sensitivity in different directions with respect to the luminance distribution, and the phase-difference detection and the contrast detection are performed according to the direction of the light-receiving sensitivity so as to perform appropriate focus detection.

1. Field of the Invention
The present invention relates to an improvement on a focus detecting device for use in a digital still camera or the like.
2. Description of Related Art
In a digital color camera, a solid-state image sensor, such as a CCD or a CMOS sensor, is exposed to an image of an object for a desired period of time in response to the depression of a release button. Then, the thus-obtained image signal, which represents a still image for one picture, is converted into a digital signal, and is then subjected to a predetermined process, such as a YC process, so that an image signal of the predetermined form is obtained. The digital image signal, which represents the picked-up image, is recorded in a semiconductor memory for every image. The thus-recorded image signal is read out, as required, to be reproduced into a signal adapted for being displayed or printed, and is outputted to a monitor or the like for displaying an image.
In such a digital still camera, heretofore, focus detection for a photographic lens is performed by using an image sensor which is provided for picking up an object image. For that purpose, in many cases, a focus detecting device of the contrast detection method is used. In the focus detection of the contrast detection method, the sharpness of an object image formed by an image pickup optical system is obtained by evaluating the output of the solid-state image sensor with a predetermined function, and the position of the photographic lens on the optical axis thereof is adjusted in such a way as to make the thus-obtained functional value become a maximum. As the evaluation functions employed in the above focus detection, there are a method of adding together absolute values of differences between respective adjacent luminance signals within a focus detecting area, a method of adding together squares of differences between respective adjacent luminance signals within a focus detecting area, a method of adding together differences between respective adjacent signals in each of R, G and B image signals, etc.
In addition, there is known, as disclosed in U.S. Pat. No. 4,410,804, a focus detecting device of the phase-difference detection method. In the focus detection of the phase-difference detection method, a pair of or two pairs of light-receiving parts are provided for respective micro lens arrays which are arranged in two-dimensional manner, and every light-receiving part is projected onto the pupil of an image pickup optical system by the corresponding micro lens array. Then, object images are formed by using two light fluxes having passed through different portions of the pupil of the image pickup optical system, and the positionally phase difference between the two object images is detected on the basis of the output of an image sensor and is then converted into the amount of defocus of the image pickup optical system.
In the focus detection of the phase-difference detection method, it is possible to obtain not only the direction of defocus but also the amount of defocus itself. Accordingly, there is an advantage that it is possible to greatly reduce a period of time required for realizing an in-focus state, as compared with the contrast detection method.
Further, there is known, as disclosed in Japanese Laid-Open Patent Application No. Sho 59-146010, a focus detecting device having both of the contrast detection method and the phase-difference detection method.
Incidentally, each of the phase-difference detection method and the contrast detection method is arranged to act by capturing the luminance distribution of an object and is, therefore, called the passive-type focus detection, which is distinguished from the active-type focus detection in which focus detection is performed by emitting rays of light toward the object from the camera.
In the case of the passive-type focus detection, the success or failure in focus detection depends on the luminance distribution of an object serving as a focus detection target. The luminance distribution exists in various ways, including a way in which the luminance is distributed in a random manner, a way in which the luminance is distributed only in the vertical direction, a way in which the luminance is distributed only in the horizontal direction, etc. For example, in a case where a person wearing vertical-striped clothes is to be photographed, if a focus detecting point is adjusted to the clothes, the luminance of the person almost never changes in the vertical direction, which is parallel with the stripe of the clothes, and greatly changes in the horizontal direction, which is perpendicular to the stripe. It goes without saying that, if there is no change of the luminance of the object, an effective output can not be obtained in the passive-type focus detection. Accordingly, it is understood that the direction of the luminance distribution giving sensitivity is an extremely important factor for the passive-type focus detecting device.
In the above-mentioned U.S. Pat. No. 4,410,804, there is also disclosed a focus detecting device of the phase-difference detection method having sensitivity both in the luminance distributions in the vertical direction and horizontal directions. Thus, the focus detection giving sensitivity both in the luminance distributions in the vertical direction and horizontal directions is realized by providing two pairs of, namely, four, photoelectric transducing parts for every micro lens. However, the provision of four photoelectric transducing parts for every micro lens necessitates the extremely-advanced minimization of a solid-state image sensor, so that it is difficult to supply such a solid-state image sensor, as an image sensor for digital cameras, at a low price.
In accordance with an aspect of the invention, there is provided a focus detecting device, comprising a sensor part arranged to receive a light flux passing through an image forming lens, the sensor part including a first pixel part having pixels arrayed in a first direction and a second pixel part having pixels arrayed in a second direction different from the first direction, and a computing circuit arranged to obtain information for focusing by performing a phase-difference computing operation for computing a phase difference between two images formed with light fluxes passing through different exit pupils of the image forming lens on the basis of a signal obtained by the first pixel part and by performing a computing operation different from the phase-difference computing operation on the basis of a signal obtained by the second pixel part.
In accordance with another aspect of the invention, there is provided a focus detecting device, comprising a sensor composed of a plurality of pixel units, each pixel unit having a first photoelectric transducing element and a second photoelectric transducing element, an optical element arranged to cause, among light fluxes passing through first and second exit pupils of an image forming lens, a light flux passing through the first exit pupil to be received by the first photoelectric transducing element of each pixel unit and to cause a light flux passing through the second exit pupil to be received by the second photoelectric transducing element, and a computing circuit arranged to compute a focusing state on the basis of a phase difference between a signal obtained by the first photoelectric transducing element of each pixel unit and a signal obtained by the second photoelectric transducing element of each pixel unit and arranged to compute a focusing state by using, as a signal for each pixel unit, a signal obtained by combining signals obtained by the first photoelectric transducing element and the second photoelectric transducing element of each pixel unit.
In accordance with a further aspect of the invention, there is provided a focus detecting device, comprising a focus detecting control part having a first mode, for small defocus, of causing a member having two aperture parts to be located between an image forming lens and a sensor part and causing a light flux passing through the two aperture parts to be received by the sensor part, and a second mode, for large defocus, of causing a light flux passing through the image forming lens without passing through the two aperture parts to be received by the sensor part, and a computing circuit arranged to detect a phase difference between two images received by the sensor part irrespective of the first mode or the second mode.
In accordance with a still further aspect of the invention, there is provided a focus detecting device, comprising a sensor part composed of a plurality of pixel units, the plurality of pixels units including at least a first array in which a plurality of pixel units are arrayed in a first direction and a second array disposed parallel with the first array, each pixel unit having a first photoelectric transducing element and a second photoelectric transducing element, the plurality of pixel units constituting the first array being disposed in such a way as to receive a light flux passing through a first color filter at intervals of a predetermined number of pixel units, the plurality of pixel units constituting the second array being disposed in such a way as to receive a light flux passing through the first color filter at intervals of a predetermined number of pixel units, every pixel unit of the second array arranged to receive a light flux passing through the first color filter being shifted by a predetermined number of pixel units from every pixel unit of the first array arranged to receive a light flux passing through the first color filter, an optical element arranged to cause, among light fluxes passing through first and second exit pupils of an image forming lens, a light flux passing through the first exit pupil to be received by the first photoelectric transducing element of each pixel unit and to cause a light flux passing through the second exit pupil to be received by the second photoelectric transducing element of each pixel unit, and a computing circuit arranged to obtain a phase difference on the basis of information on a phase difference between signals obtained by the first photoelectric transducing element and the second photoelectric transducing element of every pixel unit of the first array arranged to receive a light flux passing through the first color filter and information on a phase difference between signals obtained by the first photoelectric transducing element and the second photoelectric transducing element of every pixel unit of the second array arranged to receive a light flux passing through the first color filter.
The above and further aspects and features of the invention will become apparent from the following detailed description of a preferred embodiment thereof taken in conjunction with the accompanying drawings.

Focus detecting device determining focusing state based on phase difference information


Methods and apparatus for alignment of masks and wafers in charged-particle-beam (CPB) pattern-transfer use optical position sensors to determine the positions of a mask or a mask stage with respect to an axis of a CPB optical system. The optical position sensor uses optical reference marks provided on the mask or mask stage. Determination of the position of the mask of the mask stage permits a coarse alignment of the mask or the mask stage. CPB reference marks are provided on masks, mask stages, wafers, and wafer stages, permitting alignment of the mask stage or the mask with respect to the wafer stage or wafer, respectively, using the charged particle beam. The charged particle beam is scanned with respect to the wafer or wafer-stage CPB reference marks to determine a deflection corresponding to an alignment of the CPB reference marks of the mask and wafer (or mask stage and wafer stage). Use of the charged particle beam for such alignment permits a fine alignment.

The increasing level of integration demanded of integrated circuits such as DRAMs has increased the need to transfer high-resolution patterns from a mask to a wafer to create circuits having very small features. Pattern-transfer apparatus using an electron beam are capable of the required high-resolution imaging.
FIG. 4 shows a conventional charged-particle-beam (CPB) pattern-transfer apparatus 40. An electron gun (not shown in FIG. 4) produces an electron beam EB that illuminates a mask 2. A CPB optical system 3 situated on an axis AX projects an image of the circuit pattern defined by the mask 2 onto a wafer 5. The mask 2 and the wafer 5 are retained by respective stages 1, 4 that are provided with respective CPB reference marks 6, 7. The CPB reference mark 6 is typically a small aperture that transmits the electron beam EB. The CPB reference mark 7 includes one or more areas that can reflect the electron beam EB.
To achieve high-resolution pattern transfer, the wafer 5 and the mask 2 must be precisely positioned with respect to each other. To this end, the wafer 5 is positioned with respect to the axis AX of the CPB optical system 3 by mechanically positioning the wafer stage 4 using the wafer-stage CPB reference mark 7. The wafer stage CPB reference mark 7 is illuminated by the electron beam EB, and the reflected (backscattered) electrons produced from such illumination are detected with a backscattered-electron detector 8 that produces an electrical signal used to align the CPB reference mark 7 with the axis AX.
In addition to the CPB reference mark 7, the wafer stage 4 can include optical reference marks. In such a configuration, an optical microscope can be used to perform a coarse alignment of the wafer stage 4 with the axis AX using the optical reference marks prior to the more precise alignment described above using the CPB reference mark 7.
After the wafer stage 4 is positioned as desired, the mask 2 is aligned with the wafer 5. The mask stage 1 positions the mask-stage CPB reference mark 6 near the axis AX to allow the electron beam EB to irradiate the mask-stage CPB reference mark 6. The portion of the electron beam EB transmitted by the mask-stage CPB reference mark 6 is reflected by the wafer-stage CPB reference mark 7 and detected by the backscattered-electron detector 8. Electron-beam deflectors (not shown in FIG. 4) scan the electron beam EB with respect to the wafer-stage CPB mark 7. The amount of deflection that produces a maximum output from the backscattered-electron detector 8 corresponds to an alignment of the mask stage 1 and the wafer stage 4 with each other. This deflection is recorded and used to compute deflections necessary for alignment during subsequent pattern-transfer operations. The alignment of the mask stage 1 with the wafer stage 4 need not be performed each time the wafer 5 is changed.
After alignment of the mask stage 1 with the wafer stage 4 is complete, the mask 2 and wafer 5 are aligned using respective CPB reference marks provided on the mask 2 and wafer 5. (These reference marks are not shown in FIG. 4.) The alignment procedure is similar to that used for aligning the mask stage 1 with the wafer stage 4 using the respective CPB reference marks 6, 7. The deflection of the electron beam EB required to properly align the wafer 5 and the mask 2 is recorded and used to compute the electron-beam deflection and rotation required during subsequent pattern-transfer operations.
The conventional mask-to-wafer alignment method summarized above is adequate for small masks, but with larger masks, the conventional method is unsatisfactory. The dimensions of a large mask are less accurately controlled than those of a small mask so that the location of the mask-stage CPB reference mark 6 relative to the mask 2 is less accurately known. In addition, because the area illuminated by the electron beam EB is small, CPB reference marks can be outside the illuminated area so that alignment based on backscattered electrons from these reference marks is impossible.
In addition, for thin-film electron-scattering masks, the locations of CPB reference marks can change during use. The electron beam EB heats the mask, causing a thermal deformation of the mask. To reduce thermal deformation of the mask, an additional thin film can be deposited on an area surrounding the CPB reference mark to reduce heating. The additional thin film, however, also reduces the positional accuracy of the CPB reference marks. Thus, precise alignment is difficult.

Apparatus and methods for mask/substrate alignment in charged-particle-beam pattern-transfer


A test structure for detecting defects in a semiconductor wafer and a method for using such test structure are provided. The test structure includes conduction units arranged in an array and test pads connecting to the conduction units. A conduction unit includes closely spaced or intermeshed conduction paths. The test pads are divided into X and Y groups. A pair of test pads X(i), X(i+1) are set to high voltage, a pair of test pads Y(j), Y(j+1) are set to low voltage, and the other test pads are floated. The current I(i, j) flowing from test pad pairs X to Y is measured. If current I(i, j) is a local minimum, then conduction unit (i, j) has a short circuit defect.

1. Field of the Invention
The present invention relates to semiconductor processing, and more particularly, to a method and device for finding defects in a semiconductor process by using addressable test structure.
2. Background Information
Yield improvement is an important task in semiconductor processing. When a wafer is processed, it typically comprises hundreds of chips, or devices, that are later packaged into individual integrated circuits. After a wafer is manufactured, the wafer is examined to determine the location and types of defects. Either optical inspection of the wafer or electrical testing of the circuits on the wafer may be conducted. The defect patterns are compared with a reference set of defect patterns to identify the failure modes, and then the manufacturing process or equipment associated with those failure modes are adjusted to eliminate the cause of defects and improve yield rate.
In order to determine whether the defects on a wafer match a certain failure mode defect pattern, it is important to know the location of the defects on a wafer. Optical inspection provides an easy method to determine the location of defects caused by particles that have fallen on the wafer. However, not all particles on a wafer cause defects, as when particles fall on non-active regions. Moreover, some defects occur in the buried layers, and cannot be found by optical inspection. Thus, electrical tests are necessary to more thoroughly and accurately determine the existence and location of the defects. The electrical tests may be conducted by simply determining whether the circuitry is functional or defective. By mapping the location of the defective chips on a wafer, the failure modes can be determined and the processing steps may be improved accordingly.
The cause of defects can be more accurately diagnosed if the location of the defects within the chip can be determined. Such information can be used to generate a more detailed wafer defect map. Traditionally, the location of defects within a chip can be determined if the chip is a memory device, such as a RAM chip, a ROM chip, a flash memory chip, etc. Each memory cell within the memory chip has a unique address, and the corresponding location of a cell for each address is predetermined. Thus, the location of defects can be easily determined by testing the functionality of individual cells and mapping the location of the defective cells according to their addresses. However, such a method for determining the location of defects cannot be used for chips other than memory devices, such as logic circuit chips. Unlike memory cells, the logic gates on a logic circuit chip do not have addresses, thus there is no simple method of determining the location of defects by testing the functionality of the logic circuitry.
Therefore, what is needed is a new method of providing an addressable test structure with a small test pad area so that location of defects on a wafer can be easily determined.

Method and device for addressable failure site test structure

Taiwan Semiconductor Manufacturing Co., Ltd.


The present invention improves a current--voltage characteristic by perfectly eliminating defects in the polycrystal silicon layer of TFT by hydrogenation. In the first process, hydrogen is doped into the polycrystal silicon layer 16 of TFT 1 by the hydrogen plasma doping method to eliminate a greater part of the defects in the polycrystal silicon layer 16. Thereafter, in the second process, after an amorphous silicon nitride film 23 including hydrogen is formed on the polycrystal silicon layer 16 or on the stopper layer 17 provided on the polycrystal silicon layer 16, hydrogen is released from the amorphous silicon nitride film 23 including hydrogen by the annealing process and such released hydrogen is then diffused into the polycrystal silicon layer 16 in order to eliminate remaining defects in the polycrystal silicon layer 16.

1. Field of the Invention
The present invention relates to a method of hydrogenation of a thin film transistor (hereinafter abbreviated as TFT) to eliminate defects within a polycrystal silicon layer of TFT.
2. Description of Related Art
A polycrystal silicon TFT using polycrystal silicon as a channel region has been investigated widely in these years in view of introduction into an LCD (liquid crystal display) where an address circuit and a clock circuit are mounted on a substrate.
Much interest is taken in the process to form polycrystal silicon by the laser annealing method because this process enables forming of polycrystal silicon with a low temperature process on an economical substrate consisting of glass, plastics or ceramics.
Next, a structure of TFT will be explained with reference to a schematic cross-sectional view of FIG. 3. FIG. 3 illustrates a structure of a bottom gate type TFT under the condition before a passivation film is formed.
As shown in FIG. 3, a gate electrode 52 is formed on a glass substrate 51 and an oxide film 53 is formed on the surface of this gate electrode 52. A silicon nitride film 54 and a silicon oxide film 55 are then stacked thereon covering the anode oxide film 53.
On the silicon oxide film 55, a polycrystal silicon layer 56 polycrystallized by the laser crystallization method is formed. Moreover, a stopper layer 57 consisting of silicon oxide is formed on the polycrystal silicon layer 56 provided at the upper part of the gate electrode 52.
At both sides of the stopper layer 57, doped layers 58, 59 which will become the source/drain regions are formed and the polycrystal silicon layer 56 provided at the lower side of the stopper layer 57 becomes a channel region 60. The doped layers 58, 59 are formed, for example, of polycrystal silicon including an n-type impurity [phosphorus (P), arsenic (As) or antimony (Sb)].
These doped layers 58, 59 are respectively connected with the source/drain electrodes 61, 62.
The above-mentioned laser crystallization method is applied for quick crystallization of amorphous silicon layer, resulting in that crystal grain size of formed polycrystal silicon becomes small. Therefore, many grain boundaries exist. Therefore, it is required to reduce the defects of grain boundaries to manufacture a TFT having a lower leakage current.
Hydrogenation is one of such laser crystallization methods. The hydrogenation method is classified into the method where hydrogen is doped using hydrogen plasma and the method where hydrogen is diffused from amorphous silicon nitride film including hydrogen.
A method for hydrogenation of polycrystal silicon layer 56 of the TFT 50 explained with reference to FIG. 3 will then be explained hereunder.
With the plasma doping method using hydrogen plasma, hydrogen is doped, through the stopper layer 57 consisting of silicon oxide, to the polycrystal silicon layer 56 where a channel region 60 is formed. As a result, the polycrystal silicon layer 56 is hydrogenated.
As another method, after amorphous silicon nitride film including hydrogen (not illustrated) is formed, hydrogen included in this film is then diffused, through the stopper layer 57, to the polycrystal silicon layer 56 where the channel region 60 is formed. As a result, the polycrystal silicon layer 56 is hydrogenated.
Next, change of drain current--gate voltage characteristic (hereinafter described as current--voltage characteristic) of TFT 50 before or after the hydrogenation of polycrystal silicon layer 56 will be explained on the basis of the current--voltage characteristic of FIG. 4. In this figure, a drain current is plotted on the vertical axis, while a gate voltage on the horizontal axis.
As shown in the figure, the current--voltage characteristic of TFT 50 before the hydrogenation is indicated by a solid line (a). That is, increase of drain current is small with respect to the increase of a positive voltage applied. This fact suggests bad switching characteristic of TFT.
Therefore, after the hydrogenation process for about 60 minutes, the current--voltage characteristic of TFT 50 has been investigated again. As a result, this current--voltage characteristic is indicated by a broken line (b). As explained above, increase of drain current becomes larger with respect to the increase of the positive voltage applied. Namely, the ON/OFF current ratio becomes as much as six orders of magnitude, resulting in a larger gradient of the drain current--gate voltage curve, depending on decrease of a leak current because uncoupled hands of the grain boundaries are terminated by hydrogen.
For example, the effective diffusion coefficient of hydrogen in the silicon oxide is defined as 10.sup.-10 cm.sup.2 /s and the effective diffusion coefficient of hydrogen in the polycrystal silicon as 10.sup.-12 cm.sub.2 /s (1/10 of the value of the single crystal silicon). In this case, 10 seconds are required for hydrogenation of the polycrystal silicon film having a thickness of 30 nm.
The hydrogenation of the polycrystal silicon layer of TFT further requires a time longer than the abovementioned calculated time due to a delay of the diffusion of hydrogen since the polycrystal silicon layer is partly covered with the doped layer and source/drain electrode, etc. When it is taken into consideration, the hydrogenation time can be calculated as 2.5.times.10.sup.3 seconds, which almost matches the result of experiments.
When hydrogenation is further carried out, hydrogen in the polycrystal silicon layer becomes excessive, deteriorating the current--voltage characteristic.
However, the prior art methods explained above have the problems as will be explained hereunder.
1. Hydrogenation using hydrogen plasma generally reduces defects in the polycrystal silicon layer but cannot perfectly eliminate such defects because the hydrogen plasma certainly reduces defects but also generates new defects.
2. When TFT is exposed to the plasma for about 60 minutes or longer, deterioration of transistor characteristic can be observed because the channel region is irradiated continuously, while it is exposed to the plasma, to energy particles or ultraviolet ray which may generate defects through the stopper layer.
Here, characteristic change of TFT by irradiation of the ultraviolet ray will be explained hereunder with reference to the current--voltage characteristic change diagram of FIG. 5.
As shown in FIG. 5, a broken line (a) indicates the current--voltage characteristic of TFT hydrogenated by the plasma doping method using hydrogen plasma after irradiation of ultraviolet ray (mercury lamp, principal wavelength .lambda.=253.7 nm, 184.9 nm).
Moreover, a chain line (b) indicates the current--voltage characteristic after irradiation of the ultraviolet ray. As will be obvious from this figure, the current--voltage characteristic of TFT is deteriorated by irradiation of the ultraviolet rays.
A solid line (c) indicates also the current--voltage characteristic of TFT after hydrogenation by the plasma doping using hydrogen plasma. As is obvious from this characteristic, the current--voltage characteristic of TFT recovers depending on the hydrogenation process.
As explained above, FIG. 5 suggests that defects may be generated in the polycrystal silicon layer of TFT by irradiation of the ultraviolet ray.
As the hydrogen plasma used for hydrogenation, an intensive ultraviolet ray in the range from 110 nm to 162 nm is emitted. Since an energy of such ultraviolet ray is higher than the value discussed above, it can be sufficiently assumed that TFT may be damaged. Therefore, quality of TFT hydrogenated by the plasma doping using hydrogen plasma is deteriorated.
3. In the method for hydrogenating the polycrystal silicon layer using amorphous silicon nitride film including hydrogen (a-SiNx:H), since the amount of hydrogen released from the inside of the amorphous silicon nitride film is insufficient, defects cannot be eliminated perfectly by hydrogenation of the polycrystal silicon layer with the laser annealing process.

Method for hydrogenating a polycrystal silicon layer of a thin film transistor


The present invention relates to spheric-shaped see through lenses used in eyewear. The lenses have a substantially constant thickness and having a substantially constant radius of curvature of between 27-20 mm. The spheric lenses may be supported in a frame formed of either rigid or flexible material and attached to a strap assembly adaptable to be worn by the user. Optionally, each of the lenses may be supported by a flanged member and ventilation passages preferably extending through the frame and/or the lenses to allow air to circulate around the lenses.

The present invention relates to see-through lenses. More particularly, the present invention is directed to uniquely constructed, radically-shaped lenses, e.g., spheric or toric lenses having a radius-of-curvature between 27-20 mm (20-27 base curve), adaptable primarily for use in non-prescription sunglasses, sport goggles and the like.
Provisional Patent Application No. 60/150,803 is incorporated herein by reference for all purposes.
As well as enhancing vision, eyeglasses also serve to protect the eye against all types of foreign objects. Initially, the lenses employed in such eyeglasses were routinely made of glass and were substantially flat in shape, a condition that created significant distortion around the periphery of the lenses. More recently, lenses have been made of a variety of plastic or plastic-like materials, often having dramatically curved surfaces. For example, swim or riding goggles are well know to have teardrop-shaped lenses. While such lenses may reduce aerodynamic drag, a wearer may suffer from undesirable peripheral distortion when viewing through such lenses.
Curved lenses employed in sports goggles, sunglasses or the like may be more or less elliptical in shape as required by the specific application. Such applications may include fashion eye wear, performance eye wear including swim and sport goggles, and sunglasses, as well as all manner of protective eye wear for use at home and on the job. In any particular use, the arc of the curved lens may vary in shape dependent on the overall circumference of the curved lens necessary to achieve undistorted vision. Lenses may be employed with a slight spherical appearance, i.e., a modified spheric, or ovoid arc. In such slightly curved lenses, there is a variable radius of curvature somewhere between 106-44 mm, e.g., a 5-12 base curve. In effect, the distance between the lens and eye may well differ at different locations on the lens. This may create significant distortion at the periphery of each lens.
The Government of the United States has procured a protective facemask assembly having a pair of semi-curved lenses of spheric or ovoid configuration. While these lenses may seem superficially similar to the present invention, closer inspection reveals a number of significant differences. Because the Government lenses are mounted in pockets creating the nose bridge of the facemask, the edge of each Government lens is truncated or cut-off to allow for assembly into its respective pocket. This naturally creates peripheral distortion for the wearer of the mask, when attempting to view through the truncated portion located near the mask nose. Another drawback of the Government procured spheric lens is the use of only a single size lens, i.e., xe2x80x9cone size fits all.xe2x80x9d Each Government lens also incorporates two parts, a spheric lens and surrounding flange joined by a dedicated and detectable seam. This seam itself can distort the vision of the wearer. Furthermore, there is no suggestion that the flange surrounding the Government""s spheric lens can be made of any desirable configuration.
It is clear that there exists a need in the art for an improved viewing lens capable of providing distortion free viewing in a fashionable design equally adaptable for use in most all types of eyewear including conventional, non prescription sunglasses. As will become apparent, the present invention provides a uniquely configured Bugeyes(copyright) lens assembly which optimizes peripheral vision while minimizing the size of each lens and thus maximizing the aerodynamic flow of air around the lens.
There is a need in the art for eyewear lenses capable of providing maximum field-of-view with a minimum of distortion. Such lenses need be adaptable for eyewear including sports wear and fashion wear. The present invention provides such radically shaped lenses and associated eyewear.
The present invention is directed to a radically shaped lens adaptable for use as a viewing lens in protective eyewear, sunglasses, sport goggles, and swim wear utilized above the water. The invention includes a unique Bugeyes(copyright) lens wherein the radius of curvature of the lens is substantially constant from a normal eyeball as it scans throughout the viewing field. Because the radius of curvature is substantially constant, the radically shaped, Bugeyes(copyright) lens provides for continuous, undistorted peripheral vision. The radius of curvature of each radically shaped lens is preferably in the range of 27-20 mm, e.g., an exemplary lens with a base curve in the range of 20-27.
The Bugeyes(copyright) lens is of substantially constant thickness throughout the field of view and the lens is optically correct and free from any prism effect throughout the periphery of the lens. The lens has a 0 power of magnification at all points in the viewing field when constructed of material having an index of refraction of between 1.55 and 1.66. A further feature of the present invention is that the closer the lens is positioned relative to the eye, the smaller in size the lens needs be. The lens should be no smaller than necessary to provide freedom of movement of the wearer""s eyelashes. As the separation between the lens and the eye increases, the size of the lens will also increase, with the maximum practical size of the lens directly related to the facial geometry and to the point at which the wearer""s eyes field of vision overlap.
A pair of the radically-shaped lenses according to the present invention may be directly attached to a pair of stems (also referred to as temples) extending about opposite sides of the wearer""s head or attached to a goggle strap of any size and shape. Each radically shaped lens may include a flange portion partially or totally surrounding the viewing lens. At the point where the lens and flange intersect, a seam may exist which visually differentiates between the lens and the flange. In one embodiment of the present invention, the lens and surrounding flange are separately constructed and joined at the seam. Alternatively, the lens and flange may be integrally constructed out of the same material with a gradual transition between the lens and flange portions providing a seamless appearance. Regardless of the type of construction employed, these flanges may serve to secure the lenses to a pair of eyeglass stems, padding, nose piece, ear piece, strap or the flange may be purely ornamental. The flange can be of any size, shape, color, texture, or material. It is also within the scope of the present invention to dispense with the flange altogether by directly connecting each radically shaped lens to the goggle or glass frame.
The percentage of the spheric lens which must be used for the field-of-view should be sufficient to provide undistorted peripheral vision of at least 20xc2x0 vertical and 20xc2x0 horizontal and may be as great as 80xc2x0 to 94xc2x0 at the distal portion of each lens. As the proximal portion of the radically shaped lens, the nose would restrict overall monocular vision to field-of-view of about 140xc2x0 to 156xc2x0.

Radically shaped lenses and goggle assembies and glasses employing same


A method of making a universal joint outer member affording a cavity with axially extending grooves in the wall thereof for receiving torque transmitting balls, comprising fitting into a preformed outer member, of light weight material, one or more wear resistant elements which define the grooves, and subjecting the assembly to an extrusion operation to secure the groove-defining elements in position and form the outer member to size.

Field of the Invention
This invention relates to universal joints, for torque transmission, of the type comprising an outer member affording a cavity within which is disposed an inner joint member, the outer and inner joint members having axially extending opposed pairs of grooves in each of which pairs of grooves is received a torque transmitting element such as a ball to provide for torque transmission between the outer and inner joint members whilst accommodating relative angular displacement between the rotational axes thereof. More particularly, the invention relates to a method of making an outer member of such a joint.
The generally accepted construction for an outer member of such a joint is an all-steel cup-like component, with relatively thick walls. This is usually manufactured from a blank resulting from a forging or extrusion process, the manufacturing involving machining processes to produce the finished article of the required dimensions. However, such an outer member is relatively heavy, and weight reduction is assuming increasing importance in components intended for use in motor vehicles. It is the object of the present invention to provide a joint outer member which is of relatively light weight.


The optical image stabilizer shifts an image stabilizing element with respect to an optical axis of an optical system to reduce image shake. The stabilizer includes a lock ring which is rotatable to a lock position to limit shift of the image stabilizing element and to a lock-releasing position to allow the shift of the image stabilizing element, an actuator which rotates the lock ring to the lock position and the lock-releasing position, and a biasing mechanism which mechanically biases the lock ring rotated to the lock position toward the lock position and biases the lock ring rotated to the lock-releasing position toward the lock-releasing position.

The present invention relates to an optical apparatus such as a digital still camera, a video camera, and an interchangeable lens, and to an optical apparatus having an optical image stabilizer that shifts an image stabilizing element such as a lens to perform optical image stabilization (image shake correction).
Many optical apparatuses include an optical image stabilizer that shifts a lens with respect to an optical axis of an optical system in order to reduce image shake caused by shake such as hand jiggling.
Such an optical image stabilizer has a shake sensor which detects the shake of the optical apparatus in a pitch direction and a yaw direction, and an actuator which shifts the lens with respect to the optical axis based on outputs from the shake sensor. Moreover, many optical image stabilizers include a lock mechanism which limits (locks) the shift of the lens so that the lens is unexpectedly shifted with respect to the optical axis of the optical system when an image stabilizing operation is not performed.
Japanese Patent No. 3618798 discloses an example as a lock mechanism. In this lock mechanism, a rotatable lock member is always biased toward a lock position by spring force. When an image stabilizing operation is performed, the lock member is rotated to a lock-releasing position by an actuator (motor), and is attracted by an electromagnet to be held at the lock-releasing position.
Further, Japanese Patent Laid-Open No. 10-142647 discloses a lock mechanism in which a rotatable lock member is driven by a stepping motor.
However, in the lock mechanism disclosed in Japanese Patent No. 3618798, it is necessary to hold the lock member at the lock-releasing position by energizing the electromagnet during the image stabilizing operation. Therefore, it is necessary to continue energization of the electromagnet during the image stabilizing operation, which increases power consumption.
On the other hand, in the lock mechanism disclosed in Japanese Patent Laid-Open No. 10-142647, the lock member can be held at the lock-releasing position by utilizing cogging force (self-holding force) generated in the stepping motor in a non-energized state, which results in a reduction in power consumption. However, when rotating force which exceeds the cogging force and is caused by external force such as impact acts on the lock member, the lock member is rotated from the lock-releasing position, which may bring discontinuance of the image stabilizing operation.

Optical image stabilizer and optical apparatus


A method of reconstructing the shape of an atomic force microscope. The shape of the probe, which is represented by a tip function, is derived from an image taken of a colloidal gold ball by the atomic force microscope. Since the size and shape of the colloidal gold ball is known, the probe shape can readily be determined. After the probe shape has been determined, it is possible to deconvolve or enhance the image of a target sample. This is done by removing the effect of the probe from the target sample image. Further, it is also possible to co-adsorb the colloidal gold balls with the target sample molecules to allow the simultaneous determination of the probe shape and the sample molecule shape.

1. Field of the Invention
The invention relates to probes used in atomic force microscopy, and more particularly, to a technique for reconstructing the tip shape of the atomic force microscope probe.
2. Background of the Related Art
Technological advances in the field of microscopes have been dramatic in recent years. The first major development was the electron microscope, which provided much greater magnification than was possible with optical microscopes. In a scanning electron microscope, a stream of electrons is directed at the sample to be magnified. The high-voltage raster beam of electrons that sweeps across the sample is analogous to the raster beam across a cathode ray tube of a video monitor. In response to the beam of electrons, the sample emits a large number of secondary electrons, which are detected by an electron beam detector. The secondary electron emission from the sample varies according to the topography, composition, crystallinity, and magnetic or electronic effects of the sample. The electron detectors convert the received secondary electrons into digital data for a processor to transform into an image that can be displayed on a video monitor. One limitation of most electron microscopes, however, is that they are unable to image individual surface atoms of a sample. Those electron microscopes that are capable of providing sufficient resolution to image surface atoms are very expensive.
The next major development in the field of microscopes was the scanning tunneling microscope (STM), discovered in the early 1980's, which allowed for the imaging of individual surface atoms. In the STM, a tiny probe is positioned to a few nanometers above the surface of an electrically conducting specimen. The distance between the probe and the specimen must be close enough so that there is an overlap between the electron clouds of the atom at the probe tip and of the nearest atom of the specimen. A voltage applied at the probe causes a small tunneling current to be generated across the gap between the tip of the probe and the specimen. The probe is scanned across the specimen while maintaining a constant gap between the tip and the specimen. The scanning tunneling microscope performs the imaging by detecting the magnitude of the tunnel current developed between the probe and the surface atoms of the specimen. The resulting variations in voltage applied to the probe are translated into an image of the surface topography of the specimen. However, one limitation of the scanning tunneling microscope is that the surface of the sample must be electrically conductive.
To overcome this limitation of the STM, the atomic force microscope (AFM) was developed. For a detailed description of the AFM, refer to Daniel Rugar & Paul Hansma, Atomic Force Microscopy, Physics Today 23 (October 1990), which is hereby incorporated by reference. The AFM includes a stylus, or probe, mounted on a cantilever that is contacted to the surface atoms of the sample. The probe is scanned across the surface of the sample to obtain the surface topography at atomic resolutions. As the probe is moved, the cantilever is deflected by interatomic forces asserted by the surface atoms. To ensure that the force asserted by the probe does not alter the location of the sample atoms, the spring constant of the cantilever is much less than the spring constant between two atoms. Originally, spring deflection sensors were utilized by the AFM's to monitor the movement of the cantilever. Recently, however, the detection is performed with laser beams to obtain greater accuracy.
Another configuration used in the atomic force microscope involves positioning the probe at a distance between 10-100 nm from the sample. In this configuration, the interaction between the probe and the surface atoms is caused by longer range forces, such as magnetic, electrostatic and attractive van der Waals forces. The cantilever is driven to vibrate near its resonant frequency. Interactive forces between the tip and the atoms determine the amplitude and phase of the cantilever oscillation. Thus, as the probe is scanned across a sample, the surface contour of the sample can be determined from variations in amplitude and phase of the oscillation.
Various methods have been used to construct the probe of the cantilever. One approach is to construct the probe with fine tungsten wires. The tip is obtained by etching the tungsten wire to a point and then bending the point to perpendicularly extend from the wire. The probe can also be built with a small diamond stylus that is glued on to the cantilever. Yet another method of manufacturing the probes is by using photolithographic techniques to make the tips from silicon, silicon oxide or silicon nitride.
Currently, cantilever probes can consistently be made with a 5 nanometer (nm) radius of curvature. However, even probes of this size have problems imaging samples with rough surfaces, that is, surfaces having height variations greater than a few nanometers. On these surfaces, the lateral resolution of the AFM images is limited by the sharpness of the probe. To resolve this problem, efforts have been made to make sharper probes or by using image reconstruction, where the contribution of the probe to the image is removed. Problems with making probes having lower radii of curvature include the cost and complexity of the manufacturing process. Current reconstruction algorithms assume an ideal probe geometry, which is usually incorrect because probe tips are frequently asymmetrical. In addition, probe tips, especially sharp ones, become contaminated easily, which further distorts the shape of the tips. Other reconstruction algorithms, such as the one described in David J. Keller & Fransiska S. Franke, Envelope Reconstruction of Probe Microscope Images, 294 Surface Science 409-419 (1993), based on the geometry of the probe sliding over a photoresist grating with substantially vertical sidewalls, do not provide the resolution required for imaging small molecular structures, such as small biomolecules. Thus, a more accurate reconstruction method is desired.

Reconstructing the shape of an atomic force microscope probe

Iowa State University Research Foundation


A material that phosphoresces may be controlled and the phosphorescence may be terminated when desired. A phosphorescing material may be exposed to an energy source that causes the material to stop phosphorescing. Thus, a pattern may be written on a surface, which is phosphorescing using a coherent energy source. The written pattern, represented by darkened regions, may be recognized by users as a symbol, a graphics or text.

This invention relates generally to phosphorescent materials.
Materials that are phosphorescent glow in the dark after being exposed to an energy source generating sufficient energy to create phosphorescence. Phosphorescence is the result of electrons associated with molecules changing orbitals in a fashion, which results in the generation of light. Some phosphorescent materials glow after being exposed to energy in the ultraviolet range. Since sunlight may include sufficient ultraviolet energy, sunlight exposure may be sufficient to cause some materials, such as zinc sulfide, to glow.
As one example, zinc sulfide, after having been exposed to ultraviolet light, may emit a pale green light for a period of up to eight hours. Thus, zinc sulfide is utilized in a variety of products including children""s glowing toys and dolls, as well as a variety of non-toy products including signs and safety equipment.
Phosphorescent materials may be provided in the forms of paints, pigments, and films. Many of these films are utilized as lambertian backgrounds to uniformly light displays while others may be used for foreground elements such as shapes or text. Phosphors are available that emit a wide variety of colored light when exposed to energy within a phosphor""s absorption band.
Among the known phosphorescent materials are ZnS (green), CaAl204 (blue), SR4Al14025 (blue-green), SRAl204 (green), and Y2O2S (orange-yellow). Each of these phosphorescent materials may emit different wavelengths of light and yet may require different energy levels in order to initiate phosphorescence. Moreover, the period of time that they phosphoresce after being exposed to sufficient energy may vary.
Typically phosphorescent materials are considered xe2x80x9cone wayxe2x80x9d materialsxe2x80x94they may be turned on to phosphoresce. It is then generally considered that these materials will continue to phosphoresce until such time as they reach their ground state. Generally, it is believed that this period of phosphoresce is a function of the characteristics of the material.
Thus, there is a need for better ways to control phosphorescent materials and particularly better ways to control the way that these materials phosphoresce.

Controlling light discharged by a phosphorescent material


Apparatus for initiating the removal or stripping of a round of ammunition rom an ammunition link belt for feeding automatic weapons comprising a cam situated proximate to and rearwardly from the feed means of an automatic weapon, the cam having a surface inclining upwardly in the direction of feed so as to impart a positive forward displacement of the round to disengage the round from a link retention tab prior to the counter recoil stroke of the operating group of the automatic weapon, thereby permitting the operating group to engage the base of the round and move the round into battery with significantly reduced energy requirements.

The present invention relates to automatic weapons of the type wherein the ammunition is fed automatically into the weapon, the ammunition being contained in or mounted in a metallic link, which link and ammunition cooperate to form a belt of ammunition, such that the removal of the round from the link belt permits the ammunition links to be disengaged and automatically discarded from the weapon. In this type of ammunition belt, the ammunition round and the links cooperate so as to form a chain wherein the round acts as the pintle of a hinge pivotally connecting adjacent links.
Weapons of the type to which the invention herein is directed, are exemplified by the M-60 machine gun, the XM 235 Squad Automatic Weapon and the M-85 machine gun. These weapons are characterized by ammunition contained in belts of approximately 100 rounds each. The design conserves weight and permits the assembly of the link ammunition with the use of relatively inexpensive metal links which are readily disconnected from the round upon firing and which are of small monetary value and therefore need not be collected after firing.
The links which are utilized to connect the ammunition rounds are of such a shape and character, that they conform closely to the outer diameters of the ammunition rounds and provide a secure means for linking ammunition rounds together. Additionally, the links align the ammunition rounds so that the ammunition belt is of uniform width, i.e. the bases of the linked ammunition define a single plane. This is accomplished by an extended retention tab on each link which seats in an annular indentation near the base of each round.
Before the intentive concept can be thoroughly understood it is necessary to understand the operation of a typical automatic weapon. When ready for firing, the operating group, which contains the firing pin, is in intimate contact with the ammunition round in the chamber. When the trigger is depressed, the firing pin within the operating group contacts the base of the ammunition round thereby causing ignition of powder within the round which results in the expansion of gases and the propulsion of a projectile (e.g. bullet) through the barrel of the weapon and to the target. Energy created by the expanding gases is utilized to cause the operating group to recoil or move rearwardly from the battery position. During the course of such recoil motion, the automatic feed mechanism of the weapon places the next round in position for displacement into the chamber by the operating group. The operating group reaches its rearmost position at which point, it has compressed the drive spring, thereafter, on the counter recoil stroke, moves the operating group forward into contact with the base of the ammunition round, removing the round from the link and into the chamber. The cycle of operation is completed as the operating group again achieves battery position so that the firing pin may make contact with the round, thereby initiating the ignition of powder once again.
The present state of the art requires the operating group to completely strip the ammunition round from the link belt on its counter recoil stroke. The energy for this counter recoil stroke comes totally from the drive spring which aids in absorbing the recoil energy associated with the firing of an ammunition round. The drive spring returns the operating group to its battery position and in the process, strips the round from the link belt. It is recognized by those skilled in the art, that a weapon system capable of fully automatic firing imparts tremendous forces upon the components of the weapon (e.g. drive spring, extractor, sear, buffer, etc.) Therefore, any assistance which can be given to these components or any resistance which can be removed or reduced will have a beneficial effect upon the life of the parts of the system.

Cam actuated ammunition prestripping mechanism

The United States of America as represented by the Secretary of the Army


A method is provided for producing a hot-pressed member including heating a Ni-based coated steel sheet, which includes, on a surface thereof, a Zn—Ni alloy coating layer containing 13% by mass or more of Ni, in a temperature region of an Ac3 transformation point to 1200° C.; and then hot-pressing the steel sheet.

Many underbody parts and body structural members of automobiles have been produced by pressing steel sheets having predetermined strength. From the viewpoint of global environment conservation, weight lightening of automobile car bodies has recently been desired eagerly, and the effort to decrease the thickness of the steel sheet used by strengthening the steel sheet has been continued. However, the pressing workability decreases with strengthening of steel sheets, and thus it is often difficult to process steel sheets into desired member shapes.
Therefore, Patent Literature 1 proposes a processing technique referred to as "hot-pressing" which enables both easy working and strengthening by quenching and processing a heated steel sheet at the same time using a mold including a die and a punch. However, in the hot-pressing, the steel sheet is heated to a high temperature of about 950° C. before the hot-pressing, and thus scales (Fe oxides) are produced on a surface of the steel sheet and are separated during the hot-pressing, thereby causing the problem of damaging the mold or damaging a surface of a member after the hot-pressing. In addition, the scales remaining on a surface of the member causes a poor appearance, a decrease in coating adhesion, or a decrease in corrosion resistance after coating. Therefore, the scales on a surface of the member are generally removed by a treatment such as pickling or shot blasting, but this complicates the production process and decreases productivity.
From this viewpoint, there has been demand for a hot-pressing technique capable of suppressing the formation of scales during heating before hot-pressing and improving coating adhesion and corrosion resistance after coating of a member after the hot-pressing, and a steel sheet having a film such as a coating layer provided on a surface thereof, and a hot-pressing method using the steel sheet have been proposed.
For example, Patent Literature 2 discloses a coated steel sheet coated with Al or an Al alloy. It is described that by using the coated steel sheet, decarburization and oxidation are prevented during heating before hot-pressing, and a hot-pressed member having very high strength and excellent corrosion resistance can be produced.
In addition, Patent Literature 3 discloses a hot-pressing method in which when a steel sheet coated with Zn or a Zn-based alloy is hot-pressed, an alloy compound such as a Zn—Fe-based compound or Zn—Fe—Al-based compound, which prevents corrosion and decarburization and has a lubricating function, is produced on a surface of the steel sheet during heating before hot-pressing. It is also described that with a hot-pressed member produced by the method, particularly a hot-pressed member including a steel sheet coated with Zn-50 to 55 mass % Al, the excellent corrosion preventing effect can be achieved.
Further, Patent Literature 4 discloses a hot-pressing method including heating a steel sheet provided with a coating, which mainly contains Al or Zn, in an atmosphere having a hydrogen concentration of 6% by volume or less and a dew point of 10° C. or less at a heating temperature of an Ac3 transformation point or more and 1100° C. or less, and then hot-pressing the steel sheet, thereby achieving excellent hydrogen embrittlement resistance. In this hot-pressing method, the amounts of hydrogen and water vapor in the atmosphere during heating are decreased to decrease the amount of hydrogen entering the steel, thereby attempting to avoid hydrogen embrittlement associated with an increase in strength to over 1000 MPa.

This patent is subject to a terminal disclaimer.


A cosmetic agent for dyeing keratin fibers, in particular human hair, includes at least one special non-ionic linear silicone polymer and at least one oxidation dye pre product and/or a direct dye. The use of the at least one non-ionic linear silicone polymer leads to an improved colorfulness and/or depth of shades. A corresponding packaging unit (kit of parts) and a method for dyeing keratin fibers both include the cosmetic agent. The cosmetic agent and packaging unit including the same are used for increasing the colorfulness and/or depth of shades.

The changing of the shape and color of hair is an important field in modern cosmetics. As a result, the appearance of the hair can be adapted both to current fashion trends and to the individual wishes of the individual consumer. The fashionable color design of hairstyles or the covering of gray or white hair with trendy or natural color tones typically occurs with color-modifying agents. Apart from a high coloring performance, these agents should have additional properties, such as, for example, the increase in hair volume.
Various coloring systems are known in the prior art for providing color-modifying cosmetic agents, in particular, for the skin or for keratin-containing fibers such as, for example, human hair.
So-called oxidation dyes are used for permanent, intensive colors with suitable fastness properties. Such dyes customarily include oxidation dye precursors, so-called developer components and coupler components. The developer components form the actual dyes under the influence of oxidizing agents or atmospheric oxygen with one another or during coupling with one or more coupler components.
The oxidation dyeing agents are indeed characterized by excellent, long-lasting coloring results. For natural-looking colors, however, customarily a mixture of a relatively large number of oxidation dye precursors must be used; in many cases, direct dyes are used, furthermore, for providing nuances.
Coloring or tinting agents, which include so-called direct dyes as the coloring component, are customarily used for temporary colors. These are dye molecules that are directly absorbed onto the substrate and do not require any oxidative process to develop the color. These dyes include, for example, henna which was already known in antiquity for dyeing skin and hair. These dyes are as a rule markedly more sensitive to shampooing than oxidative dyes, so that an often undesirable shift in shades or even a visible homogeneous color loss occurs much earlier.
Lastly, a further dyeing method has attracted great interest. In this method, precursors of the natural hair dye melanin are applied to the substrate, e.g., hair; these then form bioanalogous dyes in the course of oxidative processes in the hair. 5,6-Dihydroxyindoline, for example, is used as the dye precursor in such a method. Particularly, in the case of repeated use of agents which include 5,6 dihydroxyindoline, it is possible to restore the natural hair color in persons with gray hair. Coloring can occur here with atmospheric oxygen as the sole oxidizing agent, so that other oxidizing agents need not be used. In persons originally having medium-blond to brown hair, 5,6-dihydroxyindoline can be used as the sole dye precursor. For use in persons having an originally red and in particular dark to black hair color, in contrast, satisfactory results can often be achieved only by the concurrent use of further dye components, in particular special oxidation dye precursors.
However, the oxidative dyeing agents, known in the prior art, do not always lead to the desired high coloring performance, in particular to a high colorfulness and/or a high color depth.
The object of the present invention, therefore, was to provide a cosmetic agent for dyeing keratinic fibers, which avoids or at least reduces the disadvantages of the prior art and which results in an improved colorfulness and/or color depth.
Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with this background of the invention.

Dye composition with special non-ionic linear silicone polymers


A water heater includes an exhaust hood, a heat exchange module, a main heat valve and a control valve extending downwardly in turn between a case and a plate. Inlet and outlet heads are installed on the two sides at the end of the hot water pipes respectively. Holes are punched on the case and the plate correspondingly to connect intake heads with water supply pipes going through the plate. The outlet head goes through the case and the pin connects with one water-intake hose directly. The control valve has one gas valve, one control switch and one water plate. The gas inlet of gas valve is connected with a gas can. Two pipes are installed on the water plate, which are pin connected with the intake head of the heat exchange module. With low flow capacity, the temperature of hot water output can be adjusted for direct use by a human body without mixing cold water.

Although Taiwan is located in the subtropical area, Taiwanese are used to taking a bath with hot water no matter whether it is in hot summer or in cold winter so as to stimulate blood circulation, combat fatigue and relax their body and soul. Thus, it can be seen that water heaters become a necessity in people's daily lives. As a matter of fact, as for those people living in low-latitude area, the temperature of hot water used in bathing need not reach the standard of that in the warm and cold areas. Therefore, the Taiwanese household water heater obviously fails to bring its functions into full play. In addition, most water heaters are designed with both cold and hot water taps so the temperature of flowing water can be adjusted to suit the body requirement by means of mixing hot water generated from the water heater with cold water. It apparently increases water flow capacity but in fact causes excessive unnecessary energy waste by providing overheated water, and water resource waste by mixing overheated water. In another point, as for those who are fond of camping on mountains, it is always hard to take a hot water bath in wildness because firstly it is difficult to search water resources; secondly it is difficult to heat water; and thirdly it is easy to cause fire. Campers have to rely on camping trailers if they want to take a hot water bath, but the imported camping trailer costs several millions of dollars, which cannot be afforded by the average people. If campers want to bring household water heater by vehicle, it is required to bring the bulky and heavy gas can together. It takes time and energy to both disassemble and transport them. The journey may therefore lose its meaning and it is not feasible to travel in this way.
As mentioned above, in the present water heater market, it is lacking water heaters that are energy-saving and convenient to be brought for camping. In order to meet the demand of customers and solve the problem of inconvenient usage, this new-style multi-functional water heater, which is compact easy to be brought and low in flow capacity, is invented. It is an economic water heater with comfortable hot water, the temperature of which is suitable for a human body without mixing cold water.

Water heater provided with compact design and hot water temperature for human body


A channel is inserted into a sequence of frames for an image, by varying one or more display characteristics across a display in accordance with a spatio-temporal pattern applied to, for example, successive lines of each modified frame. The channel may be employed to watermark the image, and the watermark may be defined as W(x) and its complement [1xe2x88x92W(x)] in counter-phase rotations of successive lines in pairs of frames. The watermark information is applied in relatively still portions of the image with sufficient lightness level. A receiver includes a watermark detector that has a priori information about the watermark. The watermark detector examines specific regions of the displayed image over time, and tests the regions for the watermark during time intervals when the image remains relatively still.

1. Field of the Invention
The present invention relates to image processing, and, more particularly, to a channel for data transmission in, or watermarking of, video signals.
2. Description of the Related Art
Image information is commonly processed, recorded, and/or stored in either analog or digital format, but ultimately any information recorded in an analog format may be translated into a digital format. Once in digital format, such information is easily copied, modified, or distributed through electronic media such as the Internet. While protection by copyright may be available to owners of the information once fixed in tangible media, theft through unauthorized copying, modification, or distribution of the information when it is in digital format is 1) easily accomplished and 2) difficult to detect from the information itself. For example, theft of compressed digital content (e.g., digital videodisk (DVD), digital broadcast, or digital cinema) is a serious concern to owners and providers authorized to distribute the compressed digital content. While the digital format allows for xe2x80x9cperfectxe2x80x9d copies of the compressed digital content, techniques exist to hide information within the compressed digital content that may be used to prove rightful ownership or use, such as in a court of law.
Collectively, these techniques are within the field of data verification, and for encoded and/or compressed digital image content, digital watermarking is commonly employed to insert hidden information directly into the image video signal. Many watermarking techniques for digital images have been developed that allow content providers to prove the origin of their material and that their material was copied, modified, or distributed. In addition, published techniques exist for inserting invisible watermarks into video data, and the Copy Protection Technical Working Group (CPTWG) of the DVD forum, for instance, may select a standardized digital watermarking technique for DVD""s.
For some systems, a separate data channel superimposed on the transmitted video signal may aid in data verification. The data channel may be added within the encoded video signal data stream itself, or the data channel may be sent separately in secondary channels used for system control, signaling, and/or synchronization information. The channel may be used to carry data corresponding to an encryption key, watermark pattern, or other form of identifier unique to an authorized owner or distributor of the image content.
Some watermarking techniques exploit a human""s insensitivity to high spatial and/or temporal frequencies, and insert low-level watermarks with these characteristics. As is known in the art, both electronic displays and film projectors tend to have display characteristics that vary from the center to the sides of the image. However, a human""s visual perception is such that most humans observing the image tolerate and accept these subtle variations. Because the changes in the display characteristic(s) are slight, most viewers are not aware when a display characteristic changes over time.
In many of the techniques for encoded or compressed digital images, the watermark is xe2x80x9cstampedxe2x80x9d into the image by modifying either the (analog) pixels themselves, or on selected bit values of the (digital) pixel color component values (e.g., the red, green, and blue (RGB) components). Watermarks inserted with such techniques are generally degraded or destroyed by common image signal processing methods that are applied to the digital image information, such as scaling, cropping, rotation, and compression. Furthermore, techniques for relatively high bit-rate watermarking tend to be more visible in the watermarked image and more susceptible to subsequent signal processing.
Unfortunately, the watermarks of these techniques tend to be degraded or obliterated completely when the image is resized (specifically, reduced in size) or compressed by commonly used algorithms such as those specified in the MPEG-1 or MPEG-2 standards. Furthermore, the rapid variations associated with the watermark are often interpreted as noise by signal processing algorithms compressing the image data, which tends to lower the efficiency of compression algorithms. Other pixel-domain watermarking techniques specifically target edges of objects in the image as a means for inserting a watermark or hiding data. However, since data compression algorithms such as those employed in MPEG-2 systems introduce noise at object edges, a similar degradation or obliteration of the watermark may occur.
The present invention relates to a channel allowing for watermarking of an image or data transmission within an image. The presence of the channel itself may be considered as the watermark, or the watermark may be represented by data carried in the channel. The channel is inserted into the image by varying display characteristics of the image across the display in accordance with a predefined spatio-temporal pattern. Variation of a display characteristic for preferred embodiments is based on a predefined spatio-temporal pattern within pixel pairs, pixel lines, pixel columns, or pixel diagonals of an image frame. For some embodiments the spatio-temporal pattern and a corresponding, complementary pattern are applied to corresponding successive pairs of such frames.
In one exemplary embodiment, a watermark is added to a video signal representing an image. The watermark is added by (a) applying a first watermark function to a first set of pixels in a first frame; and (b) applying a complement of the first watermark function to a second set of pixels in the first frame. In a further embodiment the relative positioning of the first and second sets of pixels tends to mask visibility of the watermark in the first frame.
In another exemplary embodiment, a watermark is detected in a video signal representing an image. The watermark is detected by (a) identifying first and second sets of pixels in a first frame; (b) calculating a first difference value for the first and second sets of pixels; and (c) determining whether the watermark is present based on the first difference value. When the watermark is present, the first difference value is related to prior application of a first watermark function to the first set of pixels and prior application of a complement of the first watermark function to the second set of pixels. In a further embodiment relative positioning of the first and second sets of pixels tends to mask visibility of the watermark in the first frame.

Spatio-temporal channel for images employing a watermark and its complement


Characteristic parameters of a torque of a stepping motor and its associated driving current or voltage are measured in advance to providetorque vs. characteristic information data representative of the torque vs. driving current/voltage characterisitcs. Then, the above characteristic parameters are measured again when a real load is applied to a stepping motor as installed with associated mechanical coupling components. An actual load torque is determined by referencing the subsequently measured characteristic parameters to the previously obtained torque vs. characteristic information data. A load inertia moment can be determined by subtracting the motor's rotor inertia moment from a determined inertia moment of the entire system. Efficiency of the motor can be determined by multiplying the output of the measured load torque by the nuber of revolutions per second thereof and dividing this by the power supplied to the motor or driving circuit. Backlash can be determined from the play in the changes of associated current waveforms corresponding to particular intervals, i.e., an interval from when the direction of rotationof the motor is changed to when the load torque increases again.

The present invention relates generally to a measurement apparatus for a stepping motor, and more specifically to an apparatus for measuring load torque, load inertia moment, output or efficiency, and backlash using a stepping motor.
Stepping motors find very wide applications in various fields as mechanical driving sources because their rotary angle and rotary speed can be controlled very accurately using digital pulses under control of a micro computer. For example, stepping motors are being used extensively in booming OA (office automation) equipment such as floppy disk drives (FDDs), hard disk drives (HDDs), printers, electronic typewriters, plain paper copy (PPC) machines, recorders, plotters, etc. and FA (factory automation) machines and equipment such as industrial robots, etc.
Load torque, load inertia moment, output or efficiency and backlash are major characteristics of stepping motors which affect development, design, production and quality control of stepping motors. Unfortunately, it is very difficult to measure such characteristics or performance with a high degree of accuracy.
For example, in measuring the load torque of a stepping motor using a spur reduction gear coupled to the mechanical component, the torque tends to vary over a wide range. That is, the load torque may be, for example, 100 g.multidot.cm if the intermeshing between the pinion gear mounted on the motor output shaft and the first stage gear is relatively loose but 300 g.multidot.cm if the above intermeshing is hard (or pushed hard). Also, the intermeshing of the subsequent gear stages affects the measurements with less influence as the stage becomes farther from the first stage. Additional influential factors include the degree of eccentricity and precision between shafts of the mechanical components, and accuracy of assembling the mechanical components such as parallelism, tension of timing belts and wires, etc.
A conventional method of measuring the torque of a stepping motor (the motor torque required by the load) is to mount a dummy motor to the system to be measured (mechanical component). The dummy motor is equal in size and shape to the actual motor but excluding coils, magnets, etc. A torque gauge is coupled to the motor output shaft in the motor pinion by way of a collet chuck or the like. The torque is measured by manually rotating the motor. Another method of measuring the torque is to use a specially designed motor having the shaft extending from both sides of the motor. The motor has the same specification as the actual stepping motor. A torque gauge is coupled to the torque measurement shaft of the motor using a collet chuck while coupling the mechanical components to the other side of the motor shaft.
Another method of obtaining the load torque T (g.multidot.cm) comprises mounting a pulley of radius r (cm) on the motor output shaft and winding a string around the pulley to measure the force F (g) using a spring scale. The torque T is determined by the following expression: EQU T=F.times.r (g.multidot.cm)
Still other methods of measuring torque include the use of a torque meter utilizing the current/torque characteristic of a DC motor and the use of a torque gauge between the motor and the load.
As mentioned above, there are many methods of measuring the torque of a motor. However, none of them is satisfactory especially in regard to measurement accuracy.
For example, in the method of using a dummy motor or a pulley and a spring scale it is difficult to provide a desired number of revolutions to the load. In the former method, it is difficult to avoid the increase in load torque due to side loading by a slanted torque gauge. In the latter method, it is also difficult to stably mount the pulley and thus to avoid the effect of side load.
In the method of using a stepping motor having the same specification as the actual stepping motor, there is a magnet in the rotor of the motor. This means that the detention torque of the magnet is unavoidably included in the measurements. When the rotor is rotated, the magnet will generate electricity in the stator coil, thereby causing dynamic braking. Also, inclination of the torque gauge will present a side load to the motor bearing in such a manner as to increase the load torque. These are causes for reduced measurement accuracy.
In the method of using the current/torque characteristic of a DC motor, it is required to disassemble the motor whenever the measurement is to be made. The load torque tends to change due to intermeshing of the pinion and gear when reassembling the motor. It is therefore difficult to know exactly how large a torque is generated by the motor in actual operation.
The above discussions lead to the conclusion that in the conventional methods for measuring torque it is impossible to measure the torque of a motor coupled to the load with a high degree of accuracy. In other words, what is needed is to know the load torque of an individual motor in quantity production with fluctuations of intermeshing of the pinion gear and the first stage gear and tension of the motor timing pulley and the timing belt. However, what is actually done is to guess the load torque by substitution means different from the actual structure. Accordingly, it has been impossible to know the torque margin or the torque generated by the motor and the load torque. The practice in production is to guarantee product reliability by performing time consuming and expensive voltage fluctuation tests, temperature tests, aging tests, printing tests, etc. before product shipment. However, when the mechanical components do not operate properly, it was necessary to spend a long time investigating the cause of trouble which may have been attributable to insufficient torque margin by designer's mistake, improper adjustment in the production line, insufficient torque due to trouble in the motor, troubles in the mechanical components, etc.
There are similar problems in measuring load inertia moment, output or efficiency and backlash of a stepping motor as a result of the above difficulties associated with the torque measurement.

Apparatus for measuring torque, inertia moment, output and backlash using stepping motor


A take-off director system provides the pilot with a visual display on a flight director indicator of the aircraft acceleration required to reach V.sub.1 speed within a length of runway calculated so that upon take-off abort the pilot will yet be able to stop the aircraft on the remaining runway; if the aircraft is not sufficiently accelerated (the accelerometer is fitted along the aircraft longitudinal axis) to enable it to reach V.sub.1 speed on a given length of runway, the system warns the pilot to abort the take-off well before reaching of V.sub.1. There is also a take-off abort warning when the pressure on the legs at V.sub.cmg speed is not reduced by a certain value depending on airport data and aircraft type. When the aircraft reaches V.sub.R speed, the system warns the pilot to pull the control column and indicates the pitch angle required to clear any obstacles.

The methodologies used for plotting aircraft take-off made available by the aircraft manufacturers are well known. Such methodologies contain instructions and nomograms with the help of which the crew can and must calculate the essential elements of a take-off.
Such instructions and nomograms, as are contained in the aircraft flight manual, imply the performance of certain complex operations by the crew, for the purpose of calculating the take-off basic parameters which are:
stabilizer angular position
take-off runway maximum length
maximum take-off weight
obstacle clearance limit
V.sub.1, V.sub.R, V.sub.2 speeds
To calculate these parameters, the pilot uses the following elements, specific to each airport;
temperature
pressure
take-off runway slope
wind direction and speed
height of obstacles located close to or remote from the airport
take-off runway length
number of turbocompressors in operation
runway condition (wet, dry)
position of center of gravity and take-off all-up weight
Even when the calculations are correctly made in accordance with the flight manual, there is still a possibility of accidents due to the following factors:
modification of temperature and pressure values between the moment the take-off elements are calculated and the moment the take-off takes place (in the case of crowded airports in unstable climatic conditions);
modification of wind speed and take-off runway condition, between the moment the take-off elements are calculated and the moment the take-off takes place;
occurance of certain failures or transient conditions at take-off leading to an increase in the value of friction coefficients, and implicitly to an increase in the time required to reach V.sub.1 ; and
payload real value much higher than that contained in the transport documents.
If two or more of the above mentioned factors making the take-off process more difficult are cumulated, a condition may occur wherein V.sub.1, the decision speed at which the pilot must decide whether to continue or discontinue the take-off, is reached too late, i.e. the aircraft has traveled too far on the runway. In such cases, if everything is operating normally, the aircraft can safely take-off; but, if before reaching V.sub.1 an engine fails, there is fire on board or some other special circumstances appear, the pilot is obliged to discontinue his take-off and, the aircraft, not being able to stop within the runway distance left, runs off the take-off runway.
At present, passenger and cargo aircraft, of either eastern or western production, are not provided with automatic or semi-automatic systems which can calculate and indicate to the pilot the best take-off process, from the flight safety point of view.


A two-speed direct-current electric motor with a high-speed rotation switch activated by a vehicular sensed parameter signal. The motor includes a motor shaft supported by at least one bearing for rotation, at least two sets of windings supported by the shaft, a contactor arrangement supported by the shaft to electrically couple the windings in first and second configurations based upon a sensed parameter signal having at least a first and a second state, and a commutator arrangement coupled to the contactor arrangement to apply electrical energy to the windings. The motor rotates at a first speed when the windings are coupled in the first configuration and rotates at a second speed when the windings are coupled in the second configuration. The high-speed rotation switch is coupled directly to a sensed parameter signal and is integral to the electric motor.

Vehicular air conditioning systems typically employ an air-cooled condenser for cooling and condensing the air conditioning refrigerant. An electric fan is used to enhance the flow of air across the condenser. Various methods for controlling the fan speed are known in the art. For example, U.S. Pat. No. 4,590,772 discloses a vehicular air conditioning system capable of adjusting draft volume across the radiator and condenser in response to air conditioner operating conditions. U.S. Pat. No. 5,285,650 discloses a controller which automatically turns off a condenser electric fan as the speed of the associated automobile surpasses a critical speed, or turns on the fan as the speed of the automobile drops below the critical speed. These references require relatively complicated control circuits and cabling external to the condenser fan motor.
Condenser fan speed controllers have also been used in refrigeration systems. For example, U.S. Pat. No. 3,122,895 discloses a condenser fan controller for a refrigeration system wherein a clutch disconnects the fan propeller shaft from a motor driven shaft when the condenser pressure drops below a certain value. U.S. Pat. No. 3,293,876 discloses a refrigeration system including control arrangement for regulating power input to the fan drive motor of an air-cooled condenser in response to the refrigeration load. U.S. Pat. No. 3,613,391 discloses a pressure-responsive motor speed control for maintaining minimum condenser pressure in a refrigeration system under varying ambient temperature and refrigeration load conditions.
Another type of fan speed controller used in vehicular air conditioning systems includes an automobile computer programmed to trigger a separate relay. The relay controls the flow of energy to a two-speed electric motor equipped with two brush sets and two commutator sets for low and high-speed rotation. The controller employs power resistors and regulators for varying motor speed. This design, however, has several disadvantages. First, the design is prone to failures leading to ineffective or unsafe conditions. For example, a computer failure may prevent the computer from commanding the relay to configure the fan for high-speed rotation at high condenser pressure or temperature. Also, controller reliability is lower due to the extra cabling and connections required between the car computer, relay and fan motor. Furthermore, the design is inefficient due to energy losses incurred by the power resistors and regulators. Finally, the design's two brush sets and two commutator sets increase the physical dimensions and weight of the motor.
Alternating-current motors in which the windings can be reconfigured by switches to vary the speed of rotation have been used. For example, U.S. Pat. No. 841,609 discloses a multi-speed alternating-current motor provided with windings which can be connected in various configurations. This alternating-current motor, however, cannot be used in direct-current applications such as vehicular air-conditioning systems.
Accordingly, it would be desirable to provide a safe and effective way to control the speed of a direct-current electric motor. It would also be useful to provide a direct-current electric motor with an integral (i.e., built-in) speed rotation switch directly activated by a vehicle sensed parameter signal, and a two-speed direct-current electric motor with a high-speed rotation switch which changes the motor speed by reconfiguring the motor windings during operation. It would also be desirable to provide a two-speed direct-current electric motor which drives a fan for cooling a vehicle air conditioning condenser based upon a sensed vehicle parameter such as the condenser pressure or temperature.

Two-speed direct-current motor with high-speed rotation switch activated by a vehicle sensed parameter signal


A system for transforming a first 3-D image of a target scene obtained from reflected energy signals to create a second 3-D image from a different perspective. In an illustrative embodiment, the original image includes multiple data elements stored in addresses of a row-column array, where each data element comprises a range and an intensity value corresponding to a point in the target scene. Each data element may be addressed by selecting its row and column numbers. To create the new image, each data element's row-column address is first converted into a spherical coordinate. The spherical coordinate is then converted into a 3-D Cartesian coordinate, and the Cartesian coordinate is translated and rotated to achieve the new perspective. The translated, rotated, Cartesian coordinate is then converted back into a spherical coordinate, and then into row-column format. Then, the contents of each data element of the original array are stored in the new array, in the newly calculated address. A "hidden surface" algorithm may be employed to remove images corresponding to surfaces that are blocked or "hidden" when viewed from the new perspective. This is accomplished by filling unused addresses of the new array with range and intensity values calculated to match that of a background plane.

1. Field of Invention
The present invention relates to an improved system for obtaining data such as range and intensity information from reflected energy signals. More specifically, the invention concerns a system for scanning a target scene with a laser light source, receiving light signals reflected by the target scene, creating a three-dimensional (3-D) image of the target scene using the reflected signals, and re-sampling the 3-D image to effectively change the perspective of the image.
2. Description of Related Art
Many different systems are known for acquiring electrical images representative of visual target scenes such as landscapes, buildings, military targets, and the like. In one example of such systems, a visual image of a target scene is obtained by a satellite. This type of system is an example of a "passive" system, since the visual image is obtained simply by sensing ambient heat or visible light reflected by the target scene, rather than by sensing reflected light generated by man-made energy sources such as lasers, radar, or other "active" energy sources. In an exemplary satellite system, the satellite detects the ambient light reflected from the target scene, and produces an array, where each element of the array represents the intensity of the reflected ambient light emanating from a designated portion of the target scene. In some applications, this array may be depicted on a multiple pixel screen, where the brightness and/or color of a given pixel may signify the intensity of light reflected by a corresponding portion of the target scene. The array is typically stored in computer memory.
Such systems have been utilized widely for quite some time, and many users have found them to be satisfactory for their purposes. However, when considered in other applications, these systems have a number of limitations. First of all, it may be difficult to interpret the data provided by these systems, since a given level of light intensity may indicate a nearby object with low reflectivity, or a distant object with high reflectivity.
As a result, some users employ passive detection systems in conjunction with "contour maps" that contain detailed terrain elevation data for the target scene. By mathematically correlating a contour map with intensity data obtained by a satellite, it is possible to determine the range in addition to the reflectivity of objects in a target scene. However, this approach has some limitations. More specifically, the resolution of many existing contour maps sometimes exceeds 100 feet, even though some applications may require resolution of six inches or less. Although this problem might be mitigated somewhat by using a custom contour map, the process of constructing such a map may be labor intensive, time consuming, and expensive.
As a result, many people have turned to laser detecting and ranging (LADAR) systems, which use light detecting equipment to record light signals that are generated by a laser light source and reflected by one or more objects in the target scene. Typically, a laser light source transmits laser light signals toward the target scene in a pattern such as a raster, star sequence, or circle sequence. Light detecting equipment, which is often co-located with the laser light source, detects light signals that are reflected by the objects and terrain of the scene. "Objects," for the present discussion, may include fixtures, trees, features of the terrain, moveable items, and other things capable of reflecting or absorbing a laser light signal. With LADAR systems, the shape, orientation, position, and other information about a distant object are derived from the intensity of the light reflected by the object. The range of the object (i.e., distance between the object and the light detecting optics) is derived from the time laser light takes to travel to and from the object.
Raw data collected by a LADAR system is typically processed by electronic processing circuitry such as a computer. During testing or development of the processing circuitry and associated algorithms, a substantial amount of data is collected. Each 3-D image generated by a LADAR system provides information about the target scene from the position of the light detecting optics when the data was sampled. The position of the light detecting optics during scanning of a target scene is the "perspective" of the light detecting optics for that image.
Sometimes after a set of data has been collected, it is desirable to have an image of the same scene, from a different perspective. For instance, it may be useful to generate a series of images of a target scene from different perspectives for use as test input data for a computer controlled guidance or tracking system. By feeding such images to the guidance or tracking system, a test engineer may monitor the system's response under simulated conditions.
A conventional approach to the need for multiple images from diverse perspectives has been to simply reposition the LADAR equipment as desired, re-transmit light signals with the laser source, and re-record the reflected light signals with the light detecting optics. Although this approach may be adequate in some applications, it is limited when used in other contexts. For example, re-positioning the LADAR equipment and re-sampling the data may be expensive and time consuming. Additionally, while it may be desirable to have an image from a certain perspective, it may be impossible in some cases to physically locate the detecting equipment at the required location.
In contrast to the conventional approach discussed above, another approach has been to use a synthetic model of a target scene to generate images of the target scene from different perspectives. With this method, computers are used to mathematically construct a detailed three-dimensional graphical model of the target scene. Then, the target scene may be viewed from any desired perspective by providing the computer with the three-dimensional coordinates of the desired perspective. Although this approach may be helpful in a number of respects, it is limited from the standpoint of complexity and realism. In particular, the synthetic model lacks "real life" aspects, such as electrical or optical noise that would inevitably be present in actual data. Consequently, if a series of synthetic images is generated as test input for a guidance or tracking system, the system's response to noise or other interference generally cannot be determined.

System for changing perspective of 3-D images obtained from reflected energy signals