A key frame animation processing method includes steps of outputting information indicating a time for presenting a key frame for every key frame, and outputting state information of each object in correspondence to the time information of the key frame for every key frame, thereby reducing the quantity of outputted data. The data may be outputted to either a storage medium or a communication medium. This method may include a step of outputting link information as to each object and another object in another key frame in correspondence to the state information of the object. The state information may include only the quantity of a state change. Also disclosed is a method of displaying a key frame animation in real time.

Method of Processing Animation by Interpolation Between Key Frames with Small Data Quantity
1. Field of the Invention
The present invention relates to an animation processing method for recording or transmitting data of an animation previously created by the technique of computer graphics or the like, and more particularly, it relates to a method of compressing key frame information for displaying an animation by generating intermediate frames between pieces of key frame information by interpolation on the basis of images on frames (key frames) serving as keys in a time series, reducing the quantity of data for recording or transmission, and regenerating the animation in real time.
2. Description of the Background Art
Moving image data such as those forming an animation consist of an extremely large number of images called frames. In order to record information of the respective frames as such, an enormous data capacity is necessary. Thus, there has been proposed the so-called video compression for compressing the data of such video information with minimum reduction of the information quantity and recording or transmitting the same.
In case of inputting dynamic images from a camera or outputting the same onto a display, the so-called raster scan technique is generally employed. The raster scan technique is adapted to decompose each frame into a plurality of horizontal scan lines, for successively scanning the respective scan lines downward from above and rightward from the left. Therefore, the technique of video compression is generally directed to raster scan images.
An animation created by the technique of computer graphics is also converted to scan line information by the raster scan technique when displayed. In case of recording data of such an animation, a method of compressing a plurality of raster scan images is employed for recording the same in general. For example, Japanese Patent Laying-Open No. 61-198877 (1986) discloses a data compression technique of improving compressibility through conditions specific to a computer animation, for compressing scan line information by the raster scan technique.
On the other hand, techniques of creating animations by computer graphics include that called key frame animation. In this key frame animation, an animation is grasped as a set of a plurality of temporally changing xe2x80x9cobjectsxe2x80x9d. In case of creating an animation, not all frames but only frames (called xe2x80x9ckey framesxe2x80x9d) forming key points of the motion are created. Then, objects of frames (called xe2x80x9cintermediate framesxe2x80x9d) other than the key frames are automatically created by interpolative calculation of objects contained in the key frames. This interpolation method is disclosed in Japanese Patent Laying-Open No. 60-191366 (1985).
The animation created by this key frame technique can be regenerated from information related not to all frames but to only partial key frames. Therefore, the data quantity is advantageously remarkably reduced as compared with the case of creating information of all frames and recording the animation. Thus, the capacity of a necessary storage medium can be reduced and the transmission time can also be reduced, for example.
In order to automatically create intermediate frames from information of key frames by interpolation, required is information as to which object changes to what object. Therefore, the aforementioned Japanese Patent Laying-Open No. 60-191366 discloses a technique of mapping of objects. Data related to such mapping must also be recorded/transmitted along with the information of key frames.
FIGS. 1A to 1D show four key frames of a certain animation along a time series. Description is now made on how to record information on objects contained in the key frames of the animation shown in FIGS. 1A to 1D in the prior art.
Referring to FIGS. 1A to 1D, objects A0 to A2, B0 to B3, E2 and E3 are painted polygons. On the other hand, objects C1, C2 and D1 to D3 are curves. It is assumed that the key frames shown in FIGS. 1A to 1D are presented at times t0, t1, t2 and t3 in the animation respectively.
As understood from FIGS. 1A to 1D, the objects A0, A1 and A2 show changes of a single object. This object is referred to as an object A. Similarly, the objects B0 to B3 show changes of a single object B. The objects E2 and E3 show changes of a single object E. The objects C1 and C2 show changes of a single object C, and the objects D1 to D3 show changes of another single object D respectively.
In order to record information on objects contained in key frames, it is necessary to previously prepare data (state information) indicating in what states respective objects are in respective frames, as disclosed in Japanese Patent Laying-Open No. 5-101160 (1993), for example, as shown in FIG. 2 in the form of a table, for example. The full text of Japanese Patent Laying-Open Gazette No. 5-101160 is invoked here by reference.
Referring to FIG. 2, the respective columns indicate the key frames correpsonding to the respective times, and the respective rows correspond to the objects appearing in the animation. The respective elements in the table shown in FIG. 2 indicate state information of the respective objects in the key frames. For convenience of illustration, it is assumed that symbols A0 to A2, B0 to B3, C1, C2, D1 to D3, E2 and E3 denoting the respective objects also indicate the state information of the objects A to E at the respective times. In the table shown in FIG. 2, further, blank spaces show that the objects do not appear on the screen at the times.
Graphics appearing in the animation are assumed as the objects A to E in this case. However, the objects may be in various formats other than graphics. In addition to graphics such as lines, polygons, circles and stereoscopic figures, the objects may be characters, volumes of sounds or music, parameters of picture quality, positions and sizes of display windows, thicknesses of lines, colors, positions of light sources, positions of viewpoints and the like.
In order to provide sound effects in a certain key frame, for example, the sound effects are introduced into this key frame as objects. In order to change the position or size of a window for displaying the animation in a certain key frame, window parameters therefor are introduced into the key frame. Thus, all various numeric parameters employed in the animation can be treated as xe2x80x9cobjectsxe2x80x9d in this specification, particularly as state values indicating the states of the objects.
When the data shown in FIG. 2 in the form of a table are previously prepared, images of an intermediate frame at an arbitrary time can be calculated by interpolating state information of objects described in key frame information on key frames around the time such as a pair of or a plurality of preceding and succeeding frames. This interpolation method is disclosed in Japanese Patent Laying-Open No. 61-191366. Well-known techniques of interpolative calculation include an interpolation method employing linear interpolation or curve approximation of spline curves or the like.
FIGS. 5A to 5D show another exemplary animation related to the so-called business presentation. These figures show key frames respectively. Referring to FIGS. 5A to 5D, objects F0 to F3, forming an object F which is the background image, remain in the same state in all key frames. Objects G1 to G3, forming an object G consisting of characters xe2x80x9cpresentationxe2x80x9d, remain in the same state in the three key frames shown in FIGS. 5B to 5D. Objects H2 and H3, forming an object H consisting of characters xe2x80x9citem 1xe2x80x9d, are with colored and white background images respectively. An object I3, forming an object I consisting of characters xe2x80x9citem 2xe2x80x9d, is displayed only in the key frame shown in FIG. 5D, with a colored background image.
FIG. 6 shows key frame information for regenerating the animation shown in FIGS. 5A to 5D in the form of a table similarly to FIG. 2. The relation between FIG. 6 and FIGS. 5A to 5D is similar to that between FIG. 2 and FIGS. 1A to 1D. Therefore, redundant description is omitted.
With reference to FIG. 11, the conventional interpolation method proposed in Japanese Patent Laying-Open No. 60-191366 is now described. It is assumed that graphics 162 and 164 shown in FIG. 11 belong to key frames which are adjacent to each other on the time base. The method disclosed in Japanese Patent Laying-Open No. 60-191366 is adapted to equally divide the time between the graphics 162 and 164 of the adjacent key frames into n, and obtain respective corresponding points in images of intermediate frames 166, 168 and 170 (it is assumed that n =3) by linear interpolation between the corresponding image graphics 162 and 164 in the key frames. Assuming that the time base progresses along arrow in FIG. 11, the key frame containing the graphic 162, the three intermediate frames containing the intermediate graphics 166, 168 and 170, and the key frame containing the graphic 164 are displayed in this order for regenerating the animation. After the display of the key frame containing the graphic 164, similar interpolative calculation is performed between this key frame and the next key frame, for regenerating the animation.
This animation regenerating method has such an advantage that the data quantity necessary for animation regeneration can be by far reduced as compared with the case of having information of all frames. In general, therefore, all items of the data shown in FIG. 2 are simply recorded/transmitted for recording/transmitting the animation by the key frame method.
FIGS. 12A and 12B illustrate a conventional recording format. For example, the data shown in FIG. 2 are recorded/transmitted as animation data shown in FIG. 12A. Referring to FIG. 12A, each time ti and state information of each object in the key frame corresponding thereto are recorded/transmitted. Arbitrary symbol x indicating absence of objects is recorded/transmitted to a portion containing no corresponding object in each key frame. The time of each key frame and symbol indicating absence of objects can be recorded/transmitted in various expressing methods. For example, the time may be expressed in a numerical value in the unit of 1/1000 sec., while a specific code may be employed for symbol x.
On the other hand, state information of objects can be expressed through commands, for example. Exemplary state information of a painted polygon and that of a curve expressed in code trains respectively are as follows:
(Example of Painted Polygon)
P c, p, n, x1, y1, x2, y2, . . . , xn, yn where P represents a command indicating that this is a painted polygon, c represents the color number of the polygon, p represents the number of the paint pattern, n represents the number of points of the polygon, and x1, y1, x2, y2, . . . , xn, yn represent the coordinates of apices of the polygon. It is assumed here that various paint patterns are previously registered on a device side.
(Example of Curve)
W c, w, n, x1, y1, x2, y2, . . . , xn, yn where W represents a command indicating that this is a curve, c represents the color number of the curve, w represents the thickness of the curve, n represents the number of points of the curve, and x1, y1, x2, y2, . . . , xn, yn represent the coordinates of the points expressing the curve.
As hereinabove described, various numerical parameters for objects conceivable in addition to graphics can be coded in the format with heads of commands identifying the parameters respectively.
In another method, the information shown in FIG. 2 is recorded/transmitted with delimiters (e.g., xe2x80x9c,xe2x80x9d) between the respective data items, as shown in FIG. 12B. In this case, no symbol xe2x80x9cxxe2x80x9d is necessary for indicating absence of objects, while the delimiters must be recorded/transmitted in addition.
In the animation for the so-called business presentation shown in FIGS. 5A to 5D among animations, the screen itself generally remains rather unchanged but new items are successively added to the screen. In order to record such an animation in the aforementioned key frame animation method, objects once appearing on the screen must be recorded in all subsequent key frames as object information, even if these objects remain absolutely unchanged. This is a matter of course since all states of objects at times forming key points must be recorded due to the interpolation between adjacent key frames. When this recording system is employed, however, the data quantity is extremely increased. Particularly when the state information of each object is large data, the necessary data quantity is acceleratingly increased since the storage capacity necessary for recording the animation information is conceivably proportionate to the product of the number of the key frames and the data quantity per object.
In the animation shown in FIGS. 8A to 8D on the other hand, data must be recorded for every key frame even for an object having the same shape as a previously appearing object. Also in this case, the storage capacity necessary for recording the animation information is extremely increased, similarly to the animation for the so-called business presentation.
Such a problem applies not only to the case of recording animation information, but to the case of transmitting the information to another computer through a network.
Also as to objects appearing only in partial key frames, some information must be recorded/transmitted for indicating that these objects are absent in the remaining key frames, leading to wasteful recording/transmission. Every time a new key frame is added, for example, state information of objects not appearing at this point of time must be newly recorded/transmitted as blanks. The quantity of such data is accumulatively increased as the number of recorded/transmitted data is increased.
It has formerly been difficult to implement such an animation regenerating method itself. Due to the recent enhancement of the throughput of CPUs (central processing units), however, this animation regenerating method is now being implemented. In this method, however, a CPU generates intermediate frames by operations, and hence the following problems arise in addition to the problem of the data quantity:
With reference to FIG. 13, it is assumed that three frames 182, 184 and 186 correspond to the intermediate frames in the aforementioned conventional method. It is also assumed that the time required for plotting is 0.1 sec. as to each frame. Namely, a time of 0.3 sec. in total is necessary for regenerating these three frames 182, 184 and 186. When this animation is regenerated concurrently with sounds in real time, the following problems arise:
The first problem arises when this animation is regenerated in a CPU whose processing speed is lower than that assumed in creation of the animation. In this case, a time of 0.12 sec., for example, longer than 0.1 sec. is necessary for plotting one frame, as shown in FIG. 14. If frames 192, 194 and 196 are successively regenerated, therefore, the regeneration takes a time longer than that assumed therefor, and the delay from the regeneration time assumed at the start is gradually increased. On the other hand, the sounds are regenerated in the time assumed at the start. Consequently, the displacement between the motions of the displayed graphics and the sounds is gradually increased. For example, the shapes of the mouth of the person regenerated on the screen are displaced from the sounds along the frames 192, 194 and 196 as shown in FIG. 14.
The second problem arises when this animation is regenerated by a CPU having higher throughput than that assumed in creation of the animation, contrarily to the first problem. In this case, a time necessary for plotting each of frames 202, 204 and 206 may be only 0.06 sec., for example, i.e., shorter than 0.1 sec., as shown in FIG. 15. Therefore, the regeneration time for the animation is shorter than that assumed in creation of the animation. If the sounds are regenerated at a constant speed, the motions are displaced from the sounds also in FIG. 15. In this case, the motions of the animation are faster than the sounds.
The aforementioned problems are caused due to the difference in throughput of the CPUs. However, such problems are also caused by fluctuations of the plotting quantity required per frame. Referring to FIG. 16, for example, consider that the size of plotted graphics is increased on the time base along frames 212, 214 and 216. In this case, the time required for plotting is increased as the graphic size is increased. For example, it is assumed that times of 0.1 sec., 0.11 sec. and 0.12 sec. are necessary for plotting the frames 212, 214 and 216 respectively. Also in this case, a delay of 0.01 sec. results in the frame 214, and a delay of 0.01+0.02=0.03 sec. results in the frame 216. Therefore, the timing for generating each frame is displaced from that for regenerating the sound also in this case.
In order to solve such problems related to synchronization of the sounds and the screen, starting times for plotting the respective frames may be decided with reference to the head frame. In this system, however, the following problem arises in the example shown in FIG. 13:
Referring to FIG. 17, consider that the throughput of the CPU is lower than the assumed one. In this case, the plotting time allocated to each of three frames 222, 224 and 226 is decided as 0.1 sec., for example. If the processing speed of the CPU is slow, it may be impossible to completely plot each graphic in the supplied plotting time. In this case, plotting of the next frame is disadvantageously started despite incomplete plotting of each frame, as shown in the frame 222, 224 or 226 in FIG. 17.
If the throughput of the CPU is higher than the assumed one, on the other hand, the following problem arises: If respective frames 232, 234 and 236 shown in FIG. 18 are regenerated by such a CPU having high throughput, only a time of 0.06 sec. is necessary for plotting each frame, for example. The time allocated for plotting of each frame is 0.1 sec. Therefore, a pause of 0.04 sec. results after completion of plotting of each frame, and the CPU is in idle during this pause. In case of making the best use of the throughput of the CPU, it must be possible to regenerate not only the three frames 232, 234 and 236 shown in FIG. 18 but five frames 242, 244, 246, 248 and 250, for example, as shown in FIG. 19. The motions of the animation are smoothed as the number of frames regenerated in a unit time is increased, and hence the pauses shown in FIG. 18 are preferably minimized so that the frames are regenerated as shown in FIG. 19.
Further, such animation regeneration is preferably applicable not only to the positions and sizes of the graphics but to colors and degrees of transparency of the graphics, thicknesses of lines forming the graphics, ratios of plotted parts to unplotted parts in broken lines, for example, forming graphics, font sizes in case of displaying characters, and the like. Similar processing can preferably be performed on movement of not only a single graphic but a graphic group consisting of a group of basic graphics. This also applies to scale percentage for displaying the group. Further, it is more preferable if an animation can be regenerated not only with simple motions but with specific changes with respect to progress of time in creation of intermediate frames from key frames.
Accordingly, an object of the present invention is to provide an animation processing method which can reduce the quantity of treated data in data processing of an animation in a key frame system, while keeping the quantity of information related to the animation.
Another object of the present invention is to provide an animation processor which can reduce the quantity of treated data in data processing of an animation in a key frame system, while keeping the quantity of information related to the animation.
Still another object of the present invention is to provide a compression method for animation information which can more efficiently compress animation information employing a key frame animation system.
An additional object of the present invention is to provide an animation regenerating method which can regenerate an animation by generating as many intermediate frames as possible between key frames while keeping a constant regeneration speed for the animation.
A further object of the present invention is to provide an animation regenerating method which can change motions of an animation in a key frame system.
The animation processing method according to the present invention is adapted to process an animation consisting of at least one object having a changeable state, and comprises a time information output step of outputting a time for presenting a key frame on the animation to a predetermined medium for every key frame, and a state information recording/transmission step of outputting state information of each object appearing in the key frame to the predetermined medium in correspondence to the time information of the key frame outputted by the time information output step for every key frame. The predetermined medium may be either a storage medium or a communication medium.
In this animation processing method, the information on the time for presenting the key frame on the animation and the state information of only each object appearing in the key frame are recorded or transmitted for every key frame by the time information and state information output steps, whereby no information is recorded or transmitted in relation to objects not appearing in the key frame. In other words, no unnecessary data are recorded or transmitted in relation to objects not appearing in the key frame. In relation to recording or transmission of the animation, the quantity of recorded or transmitted data can be reduced while preserving the information quantity of the animation. Consequently, the memory capacity for recording the animation data can be saved while high-speed data transmission is enabled.
Preferably, the animation processing method according to the present invention includes a link information output step of recording or transmitting link information as to each object appearing in the key frame and that in another key frame in correspondence to the state information of the object recorded or transmitted through the state information output step for every key frame.
The link information is further recorded or transmitted in correspondence to the state information of each object, whereby presence/absence of a certain object in a certain frame can be determined by whether or not an object linked with this object is present in a related key frame. No object information on an absent object may be included in the key frame information, whereby the data quantity can be further reduced.
According to another aspect of the present invention, an animation display method, which is adapted to display an animation of graphics on a display unit through a computer program, includes steps of preparing a plurality of pieces of key frame information each including information for specifying a display time and graphic information for specifying the features of a graphic to be displayed in a display frame at the display time, obtaining a current time for display, selecting at least two pieces of key frame information having display times before and after the obtained current time for display in the aforementioned plurality of pieces of key frame information, performing prescribed interpolative calculation between corresponding pieces of graphic information included in at least two pieces of key frame information respectively thereby creating graphic information to be displayed at the obtained current time for display, plotting a frame at the obtained current time for display on the basis of the created graphic information, and repeating the aforementioned step of obtaining the current time for display, the selecting step, the creating step and the displaying step up to a lapse of a prescribed time.
After a plurality of pieces of key frame information are previously prepared in a memory, the following operations are repeated: First, a current time for display is obtained. Two pieces of key frame information having times before and after the current time are selected. Prescribed interpolative operation is performed between corresponding pieces of graphic information included in the two pieces of key frame information, for creating graphic information to be displayed at the current time for display and plotting the graphic. No graphic information for the next frame is created until one frame is entirely plotted, whereby each frame can be completely plotted. Further, no display time is previously decided, whereby the animation can be displayed in response to the ability of a CPU, so that a CPU having high throughput creates a number of intermediate frames while that having low throughput creates a small number of intermediate frames.
Preferably, the plurality of pieces of key frame information include head key frame information related to a frame to be displayed at the head in this animation display method. This animation display method further includes a step of displaying the head frame in starting of the animation display, on the basis of the head frame information. Further, the step of obtaining the current time for display includes a step of referring to a timer in response to completion of plotting of one frame and obtaining the current value of the timer as the current time for display.
When the head frame is completely plotted, a current time for display of the next frame is obtained in response to this completion. When the frame is completely plotted at this time, a current time for next display is further obtained in response to this completion. Thus, when certain frames are successively completely plotted, frames are repeatedly created and plotted for display at the times of the completion. Thus, it is possible to make the best use of the ability of the CPU with no idle time.
The graphic information includes coordinate information on feature points of each graphic, color information of each graphic, information on the degree of transparency of each graphic, information on the thickness of lines forming each graphic, information on the ratio of plotted parts to unplotted parts of the lines forming each graphic, the size of each character font, coordinates of reference points of a graphic group, and scale percentage of the graphic group on display respectively. The graphic information may include deformation or movement of each graphic, a change in the color of each graphic, a change of the degree of transparency of each graphic, the thickness of lines forming each graphic, the mode of broken lines forming each graphic, the size of each character font, movement of a graphic group, or scale percentage of the graphic group on display, by creating and plotting graphic information in intermediate frames by interpolative operation between such pieces of graphic information.
More preferably, the creating step of the animation display method includes steps of performing interpolative calculation by prescribed linear calculation between corresponding pieces of graphic information included in two pieces of key frame information respectively, and converting graphic information obtained by this interpolative calculation by a predetermined conversion method.
A motion which is nonlinear with respect to time such as a motion accompanied by acceleration, for example, can be expressed by further converting graphic information once created by such interpolative calculation by linear calculation. Namely, changes can be obtained on the time base in the animation.
The converting step may include a step of looking up converted graphic information corresponding to the graphic information created in the creating step in a table. Graphic information once created by interpolative calculation is converted through the table for displaying the animation by the converted graphic information. An arbitrary change on the time base can be implemented on the animation.
Alternatively, the converting step may include a step of substituting the graphic information created in the creating step for a variable of a prescribed function and regarding the value of this function as the converted graphic information.
The graphic information obtained by the interpolative calculation by linear calculation is further substituted for the variable of the prescribed function to be converted, whereby a nonlinear motion can also be implemented on the animation. Further, the quantity of data necessary therefor can be reduced.
According to still another aspect of the present invention, the compression method for animation information is adapted to compress key frame information for an animation whose intermediate frames are generated and displayed by interpolation between a plurality of key frames through a computer. Each key frame information includes object information related to an object to be displayed in the corresponding key frame. The object information includes state information of the object, and link information to corresponding object information in key frame information having a predetermined relation with this key frame information. This method comprises a first output step of loading reference key frame information and outputting the same to a medium, a second output step of loading next key frame information in response to completion of outputting of just preceding key frame information, comparing each object information in the loaded key frame information with corresponding object information in key frame information having a predetermined relation with the loaded key frame information, and outputting compressed key frame information including object information including link information and state information having discrepancy with respect to the medium, and a step of repeating the second output step up to compression of all key frame information to be compressed.
The object information of the compressed key frame information includes link information and state information having discrepancy. The compressed key frame information includes no state information having no discrepancy with respect to that of the key frame compared therewith. However, the same can be restored from the compared key frame information in regeneration of the animation. Therefore, the animation can be regenerated from animation information of a smaller data quantity as compared with the conventional case of recording all state information as to each object information of each key frame.
Preferably, the key frame information having a predetermined relation in the compression method for animation information is key frame information outputted just in advance of the key frame information. The key frame information outputted just in advance is successively compared with the key frame information to be processed, for outputting key frame information including object information including only state information having discrepancy. The key frame information may simply be compared with the just preceding key frame information, whereby the storage capacity required for the processing can be reduced. The feature of the animation resides in that the number of objects changing states is generally small between adjacent key frames. Therefore, it is expected that the quantity of state information to be outputted is relatively reduced by comparing the just preceding key frame with the key frame to be processed, whereby the data quantity of the animation information can be reduced.
Preferably, the object information may further include a quantity of discrepancy as to the state information having discrepancy. State information having no discrepancy is not necessarily included. According to this method, therefore, the data quantity of the animation information can be by far reduced as compared with the prior art.
Preferably, the second output step includes steps of loading next key frame information in response to completion of outputting of just preceding key frame information and retrieving key frame information including object information which is in a relation of translation with each object information the loaded key frame information, and outputting compressed key frame information including object information including information specifying the key frame information including the object information having the relation of translation, link information and a translation quantity to the medium.
According to this method, the object information of the compressed key frame information includes the link information, the information specifying the key frame information including the object information of an object having the relation of translation with an object corresponding to the object information, and the translation quantity. Coordinate information of the object in the key frame to be processed can be restored from the object information of the object having the relation of translation and the translation quantity. The quantity of necessary data is reduced as compared with the case of recording all coordinate information of the object in the object information. The animation has such a feature that the translation quantity between the objects having the relation of translation is generally smaller than the values of the coordinates of the objects themselves. According to this method, therefore, the data quantity of the animation information can be by far reduced as compared with the conventional method.

Method of processing animation by interpolation between key frames with small data quantity


The present invention pertains to a method for nitrogen oxide reduction and flue gas reheating wherein a catalyst surface is heated to an operating temperature to facilitate a catalytic reduction reaction in the presence of relatively cool flue gas. To avoid conventional complication the catalytic reduction reaction is performed downstream of both particulate control operations and desulfurization procedures. That is, the catalyst surface itself is placed just before the stack. The method of the present invention reheats the flue gas prior to its exit into the atmosphere.

In the conventional nitrogen oxide producing technology including gas turbines, engines and power generators, fossil fuels are burnt to produce heat energy. A byproduct of this combustion is flue gas. Flue gas contains various contaminants such as nitrogen oxide (NO.sub.x) and sulfur oxide (SO.sub.x). Pursuant to certain federal environmental regulations, NO.sub.x and SO.sub.x emissions must be minimized prior to flue gas entrance into the atmosphere. To rid flue gas of NO.sub.x and SO.sub.x, it has been the practice to utilize a catalytic reduction process and a desulfurization operation, respectively, as explained more fully below.
A catalytic reduction process employs a reducing agent and a catalyst surface. The reducing agent, ammonia (NH.sub.3) for example, is injected into the flue gas upstream of the catalyst surface. At the catalyst surface the reduction reaction occurs. The catalyst surface is generally a vanadium or tungsten oxide supported on alumina.
In the catalyst reduction reaction, NH.sub.3 reacts with NO.sub.x at the catalyst surface to yield nitrogen and water vapor as shown below: EQU 4NH3+4NO-4N2.fwdarw.4N2+6H20 EQU 4NH3+2NO2+O2.fwdarw.3N2+6H2O
A catalytic reduction reaction takes place at the catalyst surface at a speed controlled largely by the particular operating temperature. The catalytic reaction above requires an operating temperature in the range of 600.degree.-850.degree. F. to achieve a sufficient speed of reaction. That is, the reaction must take place within the limited period that the flue ga contacts and passes through the catalyst surface. Once the flue gas has traveled downstream of of the catalyst surface the reaction is essentially halted, rendering removal of additional NO.sub.x impossible. Failure to provide the proper operating temperature can slow down the speed of the catalytic reduction, rendering the reaction incomplete.
Conventionally, the necessary operating temperature for the particular catalytic reaction has been achieved by reliance on the high temperature of the flue gas as it departs the boiler. The temperature of the flue gas as it departs the boiler is approximately 600.degree.-800.degree. F. and absent a separate reheating operation the temperature declines as the flue gas travels through the heat extraction system reaching a low of approximately 175.degree. F. before entering the atmosphere. Thus, commonly the catalytic surface is placed near the boiler, the point in the heat extraction system where the flue gas can be expected to have attained a temperature in the operating range of approximately 600.degree.-850.degree. F.
As shown in FIG. 1, in conventional boiler applications to achieve the necessary operating temperature the catalyst surface 6' is placed after the boiler 2' and between the economizer 4' and the air heater 8'. In this arrangement the catalyst surface is upstream of the particulate control device 10' and the flue gas desulfurization unit 12'. With this conventional arrangement the catalytic reduction reaction occurs in advance of both the flue gas desulfurization and particulate control operations as explained fully below. This positioning sequence however, has proven unsatisfactory for at least the following reasons.
In the conventional operational sequence shown in FIG. 1, the catalytic process takes place in anticipation of the flue gas desulfurization operation, wherein sulfur oxides (SO.sub.x) contaminates are removed from the flue gas before exiting the plant. Consequently, SO.sub.x contaminates are present in the flue gas during the catalytic reduction process. This generates multiple problems.
For instance, NH.sub.3 can react with SO.sub.3 contaminants to form ammonium sulfate and bisulfate, a fine, sticky white particulate. The catalyst surface being of a porous honeycomb material provides pocket areas for receipt of ammonia sulfate and bisulfate. The catalyst surface can become clogged and rendered ineffective. Thereafter, it can be difficult, if not impossible, to remove the ammonia sulfate and bisulfate from the catalyst surface. Consequently, the catalyst surface must be replaced necessitating machine downtime an hindering operation efficiency.
Ammonium sulfate and bisulfate can also contaminate or clog the air heater surfaces. The air heater may then need to be shut down and manually cleaned with water jets and steam. A further loss in machine efficiency results. Additionally, ammonium sulfate and bisulfate may form a fine particulate which can act as a smoke cloud increasing stack plume opacity. Moreover, NH.sub.3, promotes the conversion of SO.sub.2 to SO.sub.3. Higher concentrations of SO.sub.3 increase the acid dew point of the flue gas, the temperature at which sulfuric acid droplets form by condensation. As a result, in order to avoid acid condensation in the air heater, exit temperature must be increased. An energy system loss results and overall boiler efficiency is compromised.
The positioning of the catalytic surface prior to the particulate control operation in the conventional arrangement produces still more problems. Coal, typically burnt to produce heat energy, leaves residual composites of the silica fly ash in the flue gas. The silica fly ash contains sulfur oxides (SO.sub.2) and alkaline metals. As shown in FIG. 1, normally this fly ash is removed by the particulate control equipment or an electrostatic precipitator located at a point in the system where the flue gas temperature has decreased to the rang of 300.degree. F. downstream of the catalytic reduction process.
The performance of the catalytic reaction prior to the particulate control operation in effect means that fly ash remains in the flue ga during the catalytic reduction reaction. The presence of fly ash during the catalytic reduction reaction causes several difficulties. The catalyst surface can become poisoned by the absorption of sulfur oxides or the condensation of alkaline metals contained in the fly ash. The catalytic surface can be essentially rendered inoperable. Also, the catalyst surface may be fouled and/or eroded by the fly ash.
Of further relevance to the present invention is the conventional desire to reheat particular types of flue gas which have become cooled prior to their entrance into the atmosphere. This process is necessary in conjunction with relatively cool flue gas, having a temperature of less than 175.degree. F. This is because where relatively cool flue gas exits the stack into the plant, water condensation immediately occurs causing unsightly white colored clouds of steam deposits. To avoid these white deposits, as illustrated in FIG. 1, flue gas is typically reheated just prior to its departure from the stack. The reheating procedure raises the flue gas temperature above 175.degree. F. facilitating an upward flue gas velocity or buoyancy. Consequently, better atmospheric dispersion of the flue gas can be accomplished. Nonetheless, a separate reheating operation demands excessive energy consumption and is a costly procedure.
The present invention solves the foregoing problems of the conventional catalytic reduction process and simultaneously provides an efficient means for the reheating of flue gas. The present invention eliminates the difficulties inherent in employing a catalytic reduction operation upstream of both the flue gas desulfurization and particulate control processes, as outlined above, by placing the catalytic reduction operation downstream thereof. In the present invention, the catalytic reduction process is positioned just before the flue gas exit from the stack. As a result, the flue gas temperature upon encountering the catalytic reduction operation is incidentally increased. A dual benefit results whereby the nitrogen oxide is removed and the flue gas is reheated. A separate reheating steps is avoided, energy is saved and an otherwise loss in system energy is made beneficial.

Method for nitrogen oxide reduction and flue gas reheating


Access control within a network is established by combining multiple factors to prevent unauthorized access to a computer and/or network target system. The factors which may be combined are selected from a combination of three main factors confirmation that the accessing device which is attempting access is by an authorized user; the access request is made by a device that corresponds to an authorized degree of importance; and the accessing device is connected from a network that corresponds to the authorized degree of importance.

The present invention relates to network security, and more specifically to access control to a network using information on devices and access locations of the devices.
Traditional systems of various types are built on authorization schemes that are only based on whether or not a user is an authenticated, which is usually validated based on only a combination of user entered user id and password. As a result, if leakage of information necessary for authentication such as the user's password occurs, any party will be able to gain unauthorized access to a target system.
Some web systems use persistent or permanent cookies of browsers and provide warning of a connection having been made from a new environment. However, they do not provide forcible access rejection schemes. Also, the use of cookies implies that systems that do not involve browser-based application cannot incorporate this authorization methodology.
Even if an authenticated or valid user accesses the system, in some cases, the access of the user to the target system should be rejected. For example, when the authenticated user accesses a target system from a device that is not approved as an authorized device (e.g., a private device and/or shared ones with another person), when the authenticated user requests access from an approved device that resides in an environment with insufficient security level (e.g., access via a public Wi-Fi network), or when access to a target system is dependent on different security levels which is specified by devices, such as PCs and smartphones or operating systems such as Microsoft Windows, Mac OS X, and Linux.

Access control using information on devices and access locations

International Business Machines Corporation


A method and device includes a first conductor formed on a first dielectric layer as a partial turn of a coil. A second conductor is formed on a second dielectric layer that covers the first dielectric layer and first conductor, the second conductor forming a partial turn of the coil. A vertical interconnect couples the first and second conductors to form a first full turn of the coil. The interconnect coupling can be enhanced by embedding some selective magnetic materials into the substrate.

Current organic substrates are formed in a symmetric process that results in metal and dielectric layers fabricated on both sides of a core material. As layers are being fabricated, layers fabricated at the same time have the same thickness, including copper layers used to form patterned conductors. Inductors formed of copper, are inherent limiters from a power delivery perspective. Making copper lines thinner to achieve a greater inductance, also increases the resistance of the lines, further decreasing performance relative to power delivery.
One proposed solution is to utilize discrete component inductors, which will reduce dependents on thinner copper conductors. However, such discrete components will not address the ability to deliver power to other power planes in a substrate.


A memory card connector assembly (10) includes a pair of memory card connectors (12, 14) stacked together wherein an independent auxiliary alignment socket (40), which is aligned with but spaced from the connector housings (20), and directly mounted on the board (100), incorporates the contact tails (25) of the upper connector (12) for efficiently establishing electrical and mechanical connection between the upper connector (12) and the board (100) on which such memory card connector assembly (100) is seated.

1. Field of The Invention
The invention relates to interface means for use with stacked memory card connector assembly, particularly to an elongated socket having contact tails therein for SMT (Surface Mount Technology) on a PC board on which such socket and an adjacent stacked memory card connector assembly are seated wherein such socket is spaced from such memory card connector assembly, and mechanically and electrically interconnects the contacts of the upper connector of such memory card connector assembly.
2. The Prior Art
Memory card connectors are popularly used in the recent years because miniaturization and flexibility of the computer are the trends in the computer industry. It is common for the computer manufacturer to arrange two memory cards in a vertically close relationship in usage for saving the space in the computer, and therefore, obviously such two memory card connectors which are adapted to receive the corresponding two closely spaced memory cards therein, respectively, are designedly stacked together vertically in compliance with the configuration of such two closely spaced memory cards.
U.S. Pat. Nos. 5,149,276, 5,176,523, 5,286,207, 5,290,174 and 5,318,452 disclose two memory cards stacked together in a vertical direction for reception of two corresponding memory cards therein; Similarly, U.S. Pat. Nos. 4,810,203, 5,324,204 and 5,334,046 also disclose two-unit memory card connector assembly enclosed in a unitary housing for reception of two corresponding memory cards therein. It should be understood that because the dimension of the contact gets tinier and tinier, it is uneasy to directly precisely bend the tails of the contacts of the upper connector in place with regard to the PC board on which such connector assembly is mounted. In other words, the vertical distance between the upper connector and the PC board increases uncertainty of the true position of the tails of the contacts of the upper connector. Without any auxiliary device to align the tails of the upper connector, the defect ratio may be increased due to misalignment of the contact tails of the upper connector; otherwise, the strict precision of the manufacturing process may be required that substantially increases the cost. To avoid the aforementioned disadvantages, most stacked type connector assemblies include auxiliary devices for aligning the tails of the upper connectors regardless of whether they are the memory card type connector or the other types. In some Input/Output connectors, some means which electrically and mechanically connect the contact tails of the upper connector to the corresponding traces of the PC board are disclosed in U.S. Pat. Nos. 4,818,239, 4,878,856, 5,044,984, 5,080,609, 5,085,590, 5,267,876 and 5,336,109.
As shown in the aforementioned U.S. Pat. No. 5,286,207 (having the same assignee with the invention) and U.S. Pat. No. 5,334,046 which belong to memory card connectors, or U.S. Pat. Nos. 4,818,239, 4,878,856, 5,044,984, 5,080,609, 5,085,590 and 5,267,876 which belong to Input/Output connectors, most such auxiliary alignment devices are required to be operatively attached, integrally or separately, to the connector housing for fastening said auxiliary alignment device in place. Accordingly, generally the housing of the lower connector needs to include an extended rear portion to incorporate such auxiliary alignment device. In other words, it is required to make another special mold for manufacturing such extended connector housing instead of a common set of mold which is adapted to manufacture the general standard connector.
Accordingly, an object of the invention is to provide an independent auxiliary alignment socket for use with a memory card connector assembly including a pair of single memory card connectors stacked together in a vertical direction. Such alignment socket substantially has no relation to the connector housing so that it is unnecessary to make another specific mold for the lower connector to incorporate such socket. Thus, the cost of manufacturing can be saved.

Independent socket for use with stacked memory card connector assembly


A display apparatus and a voltage calibration method are disclosed. The display apparatus includes a ramp voltage generator, a ramp counter and a timing controller. The ramp voltage generator is configured to generate a ramp voltage. The ramp counter is coupled to the ramp voltage generator and configured to start counting when the ramp voltage generator generates the ramp voltage. The timing controller is coupled to the ramp voltage generator and the ramp counter respectively. When the ramp voltage is increased to be equal to a reference voltage, the timing controller compares an instant count value of the ramp counter with a default value and selectively calibrates a rising slope of the ramp voltage generated by the ramp voltage generator according to a comparing result of the instant count value and the default value.

1. Field of the Invention
The invention relates to a display; in particular, to a display apparatus and a voltage calibration method.
2. Description of the Prior Art
Please refer to FIG. 1. FIG. 1 illustrates a schematic diagram of the driving method of the ramp source driver in the conventional display apparatus.
As shown in FIG. 1, in the conventional display apparatus using OLED On Silicon micro-display technology, the ramp source driver generates a ramp voltage VRAMP through a ramp voltage generator RVG and transmits the ramp voltage VRAMP to all data lines DL(X) through a buffer BF.
When the value counted by the ramp counter RCT is equal to the default value stored in the data register DTR (for example, both are N), the switch SW coupled between the buffer BF and the data line DL(X) is turned off immediately. At this time, the voltage on the data line DL(X) is the voltage value of the ramp voltage VRAMP generated by the ramp voltage generator RVG.
However, in fact, in this circuit architecture, the following factors may cause the voltage values sampled on the data line to be inconsistent.
At first, the ramp voltage generator RVG basically charges the fixed capacitor through a fixed current source to generate a ramp voltage VRAMP having a fixed rising slope (as shown in FIG. 2), thereby providing different gray scale voltages required for the display panel. However, since the current source and the capacitor will change with the variation of process, voltage and temperature, the ramp voltage VRAMP provided by different driving circuits will have different rising slopes, which needs to be improved.
In addition, the ramp counter RCT is coupled to the oscillator OSC, and the oscillator OSC provides oscillator frequency to the ramp counter RCT. Since the oscillator OSC also changes with the variation of process, voltage and temperature, the time at which the switch SW is turned off each time (for example, T shown in FIG. 2) is inconsistent, so that the ramp voltage values sampled on the data line DL(X) are also different and need to be improved.

Display apparatus and voltage calibration method


Apparatus and methods for aligning heavy metal plates during tank construction using an alignment device, which is temporarily attached to the heavy metal plates with a pair of locking members pivotably coupled to a frame and a pair of adjustable alignment members attached to the frame between the pair of locking members. The alignment device may be attached to the heavy metal plates without the inefficiencies, hazards and other disadvantages associated with welding.

Storage tanks for cryogenic liquids typically include "double" and "full" containment storage tanks for cryogenic liquids. It is not uncommon for such storage tanks to have a form of secondary containment. An outer concrete containment wall can provide secondary containment in the event of a leak in the inner tank. The inner tank is typically made of 11.8 m×3.3 m heavy metal plates comprising stainless steel, aluminum, 9% nickel steel, or other materials suitable for low-temperature or cryogenic service. The inner tank is approximately 33 m tall and has a diameter of approximately 88 m.
The inner tank is typically constructed by positioning a pair of heavy metal plates adjacent one another, using a crane, to form a vertical seam therebetween. A plurality of conventional key plates (FIG. 1) are then welded to one or both of the heavy metal plates adjacent the vertical seam to align the heavy metal plates before the vertical seam is welded. In FIG. 1, each key plate 100 is held in place over the vertical seam 102 by a pair of blank nuts. Each blank nut is welded to a respective heavy metal plate 104, 106 adjacent the vertical seam 102. The key plate 100 is placed over the pair of blank nuts and is secured in place by a pair of bull pins 108, 110. Each bull pin 108, 110 is inserted through a respective opening in the key plate 100 and a respective opening in a respective blank nut. Additional bull pins may then be inserted through the key plate 100 to contact and force one of the heavy metal plates 104, 106 into alignment with the other one of the heavy metal plates 104, 106. At least four (4) and up to ten (10) bull pins may be required to align the heavy metal plates. These bull pins may be used in combination to push the vertical seam 102 out, pull the vertical seam 102 in, open the vertical seam 102 and close the vertical seam 102. Once the heavy metal plates 104, 106 are aligned, a plurality of finger bars 112 are welded to the heavy metal plates 104, 106 over the vertical seam 102 to maintain alignment while the vertical seam 102 is tacked. Because the key plate 100 and finger bar 112 must be welded to the heavy metal plates 104, 106 and forcibly removed by breaking the weld, welding equipment, fire protection, hammers and grinding/polishing equipment are required on site. This process takes time and is subject to numerous work hazards related to welding, hammering bull pins, falling bull pins, stray objects, projectiles, metal splinters and pinch points created by the bull pins and key plate 100. In addition, the key plate 100 cannot adjust to multiple radii because it is flat.
Once enough heavy metal plates have been welded together to form a bottom ring of the inner tank, then next ring is constructed by positioning a plurality of shims (FIG. 3) on a top edge of the bottom ring that will separate the next ring. The next ring is typically constructed in the same manner as the bottom ring by positioning a pair of heavy metal plates adjacent one another on top of the plurality of shims to form a vertical seam therebetween and a horizontal seam between the bottom ring and the pair of heavy metal plates in the next ring. In FIG. 3, each shim 300 must be manually held in place on the top edge 302 of the bottom ring 304 with a pin 301 on one side of a heavy metal plate 306 in the bottom ring 304 while another heavy metal plate 308 is lowered on top of the shim 300 to form a horizontal seam between the heavy metal plate 306 and the another heavy metal plate 308 in the next ring. Once the heavy metal plates 306, 308 are in place, a wedge 312 is inserted through an opening in the shim 300 on another side of the heavy metal plates 306, 308 and is hammered down until the shim 300 is secure. A plurality of conventional key plates (FIG. 1) are then used to align the heavy metal plates in the next ring in the same manner described hereinabove. This process continues until each vertical seam in the next ring is welded. The heavy metal plates in the bottom ring 304 are then aligned with the heavy metal plates in the next ring using a plurality of conventional U-Bars (FIG. 2).
In FIG. 2, each U-Bar 200 is welded in place above the horizontal seam 202. A bull pin 204 is inserted through the U-Bar 200 to align the heavy metal plates 306, 308. As the heavy metal plates in the bottom ring 304 are aligned with the heavy metal plates in the next ring, the horizontal seam 202 is welded and each shim 300 is removed by hammering the wedge 312 up to remove it and hammering the shim 300 out. Besides the inefficiencies and hazards associated with using U-Bars, removing each shim is also subject to numerous work hazards related to hammering wedges in and out, falling wedges, stray objects, projectiles, and pinch points created between the shim and the heavy metal plates. Each ring of the inner tank is constructed in the same manner thus described, which is time consuming, hazardous and requires different types of equipment and skilled labor to complete.


A touch panel comprises a substrate 11 allowing acoustic wave to be propagated and a transducer 13a, mounted to this substrate, for transmitting or receiving the acoustic wave. A chamfered portion 16 is formed in the end face or the corner portion of the substrate 11 to make the acoustic wave turn around and be propagated from the front surface to the rear surface through the end face of the substrate 11. The acoustic wave propagated through the chamfered portion is received by the transducer 13a placed on the rear surface of the substrate 11. The radius (R) of the chamfered portion 16 of the substrate is 0.5 mm or more. This touch panel may prevent from forming raised portions on the front surface of the propagation medium, so that the touch panel may be enhanced in applicability to thin LCD monitors, and simplified in structure.

The present invention relates to a touch panel (or a touch sensor or touch screen) to input/output coordinate information on touch-positions touched with fingers or the like, and more particularly to a touch panel (or a touch-position detecting device) having transmitting and receiving elements to utilize acoustic wave (e.g. surface ultrasonic wave).
As primary type of the touch panels, there have been known the surface ultrasonic wave type, the resistance film type, the electrostatic capacity type, the electromagnetic induction type and others. Among these types, the surface ultrasonic wave type includes one known method in which transmitting and receiving transducers are placed opposite each other in both directions of X and Y axes of the surface of a propagation medium, such as a glass substrate, to detect the touch-positions.
On the other hand, as a widely popularized method in recent years, there has been known a method in which respective pairs of transmitting and receiving transducers (four transducers in total) for detecting respective X and Y coordinates or coordinate values are placed in a propagation medium through an array of reflective elements to detect the touch-positions (U.S. Pat. No. 4,746,914, U.S. Reissue Pat. No. 33151 and International Patent Laid-Open Publication WO 96/23292). In this method, a wend face type transducer is used to simultaneously switch over a transmitting circuit and receiving circuit of an electric signal processing circuit (controller) in order to process respective signals of X and Y axes. Using such a signal processing leads to two partially or entirely duplicate groups not only of the switching circuit but also of the transmitting and receiving circuits in the controller, which results in complicated circuit structure and signal processing as well as increased cost.
Further, when the aforementioned transducer is mounted on the surface of the propagation medium, a raised portion is formed on the surface of the propagation medium. This makes difficult to arrange a liquid crystal display apparatus (LCD), particularly a thin LCD monitor to the propagation medium.
Thus, it is an object of the present invention to provide a touch panel or touch-position detecting device capable of preventing from forming raised portions on the surface of the propagation medium to enhance applicability to the thin LCD monitor and to simplify its structure.
It is another object of the present invention to provide a touch panel capable of reducing the number of transducers and simplifying circuit structure and signal processing.
The inventors of the present invention noted the fact that a small gap was essentially caused between the rear surface of a propagation medium (panel) and a display apparatus. As a result of their sedulous studies for achieving the aforementioned object, they have found out that when the end face or corner portion of the propagation medium allowing acoustic wave (surface ultrasonic wave) to be propagated was chamfered or rounded, the acoustic wave could turn around and be propagated from the front surface to the rear surface of the propagation medium, or from the rear surface to the front surface of the propagation medium, through the chamfered portion (rounded portion or propagation-direction changing portion), and the present invention eventually has been completed.
Specifically, a touch panel (touch-position detecting device) according to the present invention comprises a medium allowing acoustic wave to be propagated and a transducer, mounted on this propagation medium, for transmitting and receiving the acoustic wave, wherein the end face or the corner portion of the propagation medium is chamfered. In such a touch panel, the acoustic wave may be propagated bidirectionally between the front and rear surfaces of the acoustic wave propagation medium through the chamfered portion (propagation-direction changing portion). Thus, the transducer may be mounted on the front surface and/or rear surface of the acoustic wave propagation medium. In the touch panel, the corner portion of at least one of the front and rear surfaces of the acoustic wave propagation medium and the side surface of the acoustic wave propagation medium (i.e. an edge at which the front or rear surface of the propagation medium intersects the side surface thereof) is chamfered, and then a transducer may be mounted on the side surface of the propagation medium.
Further, when the end face is chamfered, the acoustic wave may be propagated in the reverse direction (i.e. from an X-axis direction to a negative (xe2x88x92) X-axis direction) through the chamfered portion (direction changing portions), and otherwise, when the corner portion is chamfered, the acoustic wave may be directionally changed from the X-axis direction to a Y-axis direction through the chamfered portion (direction changing portions).
Furthermore, when a V-shaped (or valley-shaped) cut portion or an chevron-shaped raised portion is formed and this cut or raised portion (direction changing portion) is chamfered, the acoustic wave propagated from the X-axis and Y-axis directions on one surface of the propagation medium may turn around and converge through the chamfered portion (direction changing portions). In other words, when the acoustic wave are transmitted from a convergent portion on another surface of the propagation medium, the acoustic wave on the one surface of the propagation medium may be propagated with making it branch into the X-axis and Y-axis directions. Thus, the transducer may be mounted at the aforementioned convergent area or branch area, and this allows a single transducer to transmit and receive the acoustic wave in the X-axis and Y-axis directions.
Utilizing such a chamfered portion (direction changing portion) allows the acoustic wave to be propagated from one surface to the other surface of the propagation medium, so that at least one transducer may be mounted on the rear surface of the propagation medium. For example, the transmitting and receiving transducers may be made up of two or three transducers.
The radius (R) of the aforementioned chamfered portion is typically 0.5 mm or more.
The present invention also includes a touch-position detecting device comprising a medium which allows acoustic wave to be propagated in the X-axis and Y-axis directions thereof, at least one transmitting transducer, mounted on the propagation medium, for generating the acoustic wave in the X-axis and Y-axis directions, a chamfered portion (direction changing portion), formed at the end face and/or corner portion of the propagation medium, for making the acoustic wave from the transmitting transducer being propagated from the front or rear surface to the rear or front surface of the propagation medium, and at least one receiving transducer, mounted on the propagation medium, for detecting a touch-position of the X-axis and Y-axis coordinates by use of the acoustic wave which has turned around and been propagated through the chamfered portion.
Such a touch panel utilizes a characteristic that acoustic wave (e.g. surface ultrasonic wave or the like) is propagated straight on the surface of a propagation medium. Specifically, when the acoustic wave turns around the end face of the panel, it spirally travels on the surface having semicircular shape in section. Thus, the acoustic wave generated on the rear surface of the touch panel turns around the end face of the panel and is then guided to the front surface as a touch surface. When the acoustic wave are propagated on the surface of the propagation medium, the traveling direction of the acoustic wave may be easily understood by referring a development view for the propagation medium which is a hollow and made up only of a shell. For example, as shown in FIG. 1, the traveling direction (see the arrow) of the acoustic wave traveling on the spherical surface of a sphere 1 corresponds to the outline of a section made by cutting the sphere along a plane including the center of the sphere 1. As shown in FIG. 2, when acoustic wave travels on the surface of a columnar propagation medium 2, it spirally travels on the surface of the propagation medium as shown by the arrow. Thus, when the end face or corner portion of the propagation medium is chamfered and processed into a gentle surface (curved surface), the acoustic wave are directed from one of the front and rear surfaces of the propagation medium to another surface practically without any loss.
The term xe2x80x9csurfacexe2x80x9d herein refers to the vicinity of the surface of a propagation medium or the surface layer of the propagation medium, on which acoustic wave is propagated.


A method of optimizing drill bit design and an optimized drill bit for drilling a well into an earth formation comprising a bit body; a number of blades spaced around the bit body, each blade having a curved outer edge and a forward face; a first row of cutter pockets recessed into the face along the outer edge of each blade; a second group of cutter pockets recessed into the face of each blade offset from the first row; and a plurality of cutting elements, each cutting element being brazed into a different one of the cutter pockets.

1. Field of the Invention
The inventions disclosed and taught herein relate generally to drill bits for drilling wells; and more specifically related to drill bits with super-abrasive cutting elements for drilling wells in earth formations.
2. Description of the Related Art
U.S. Pat. No. 1,923,488 discloses "a well drilling tool, such as a bit or the like, that embodies a simple, practical and improved cutting means whereby the tool is self-sharpening through use."
U.S. Pat. No. 3,140,748 discloses "an earth boring drill bit of the rigid bearingless type, known as a drag bit. Although the JQ emphasis in this application is on the use of such a bit in drilling through earth formations for oil, gas, and the like, it is to be understood that the invention is also useful in other earth boring applications, including mining and quarrying. Drilling bits that are characterized by long life under the above operating conditions, and that are also characterized by rapid penetration in a variety of formations from soft to hard, by low frequency of "pulls," by maintenance of substantially full hole gauge and by limitation of hole deviation within allowable limits, are very valuable to the petroleum industry. In addition, a satisfactory bit should be self-sharpening; and it should also have a certain geometry to penetrate rapidly through various formations. Where this geometry is initially present in the bit, it should be retained as the bit wears in use. In some cases, however, the desired bit geometry is created only as the bit wears in use and, once created, should be retained during further use. It is accordingly among the objects of this invention to provide a rotatable drag bit that will have the desirable characteristics mentioned above, including the capability of drilling in hard formations at a faster rate over longer periods of time than is obtainable with conventional bits, that will maintain a substantially full gauge hole in hard and abrasive rock formations, that will be self-sharpening, and that will have a wear pattern in use that will retain or create a desirable geometry for the bit."
U.S. Pat. No. 3,145,790 discloses "[a] milling tool (10) for processively cutting away a section of casing (14) installed within a well from the upper annular end (12) of the casing (14). The milling tool (10) includes a plurality of elongate blades (32) equally spaced from each other at intervals between one and three inches about the periphery of the cylindrical body (18) of the milling tool (10). The blades (32) are inclined with respect to the axis of rotation and hard carbide cutting discs (34) arranged in horizontal rows on the blades (32) form the inclined leading planar face of the blades (32), and the lowermost row of discs (34) forms a cutting edge with a negative rake engaging the upper end (12) of the casing (14) in a cutting operation."
U.S. Pat. No. 4,533,004 discloses "[a] self-sharpening rotary drag bit assembly comprises: (a) a carrier body adapted to be rotated about a first axis, and having a drilling end, (b) cutters carried by the body to be exposed for cutting at the drilling end of the body, the cutters having thereon layers of hard materials defining cutting edges to engage and cut the drilled formation as the body rotates, the cutters also including reinforcement material supporting said layers to resist deflection thereof under cutting loads, (c) said body and said reinforcement material being characterized as abradable by the formation as the bit drilling end rotates in engagement with the formation."
U.S. Pat. No. 4,719,979 discloses "[d]rag-type drilling bits are disclosed which have at least one blade and a plurality of fluid flow channels incorporated in the blade for conducting drilling fluid or drilling mud from the hollow interior of the bit to discharge or ejection ports located in the front cutting edge of the blade. Rods of diamonds or of like "hard" cutter insert materials are incorporated in the blade in such a configuration that as the blade wears away or erodes and small pieces of diamonds are lost during drilling, more diamonds are exposed to the formation for drilling. During erosion or wear of the blades, the fluid discharge ports continue to operate to eject drilling fluid adjacent to substantially each diamond rod, whereby the flushing away of cuttings and cooling of the diamonds is greatly improved. In some embodiments of the invention rods of alternating hard and soft materials are also disposed substantially parallel with the diamond or like "hard" cutter insert rods. When the soft material of the rods is exposed for drilling the formation, kerfs are formed which are thereafter "chipped away" by the subsequently exposed hard material of the rods."
U.S. Pat. No. 4,813,500 discloses "[a] fishtail type drag bit having abradable cutter blades attached to a body of the bit is disclosed. A multiplicity of axially aligned tubes are welded together to form a blade each blade being sustantially parallel with an axis of the bit body. Each tube of the blade contains an annulus of a diamond cutter material matrix. The center of the annulus forms a fluid conduit that communicates with a fluid plenum chamber formed by the body of the bit. The cutting edge of the diamond matrix therefore, is always immediately adjacent the fluid nozzle regardless of the degree of blade erosion during operation of the bit in a subterranean formation."
U.S. Pat. No. 4,913,247 discloses "drill bits [that] include a body member with cutter blades having a generally parabolic bottom profile. The cutter blades each include a diamond cutting face which increases in vertical height generally as a function of increased distance from the center line of the bit. The increased height allows the bits to provide a desired total diamond cutting volume at each radius of the bit, while allowing the diamond contact area to remain generally constant as the bit wears."
U.S. Pat. No. 5,025,873 discloses "a rotary drill bit including a cutting structure comprising an array of cutting elements oriented and arranged to facilitate concentration of the load on bit on groups of cutting elements until the elements become dulled or worn, at which point fresh cutting elements are exposed to engage the formation and tube the concentrated bit loading. Preferably, the cutting elements are configured and/or supported to break away from the cutting structure when worn to a certain extent, thereby facilitating exposure of fresh cutting elements to engage the formation."
U.S. Pat. No. 5,103,922 discloses "[a] fishtail type drag bit is disclosed consisting of multiple blades, each blade forming radially disposed grooves. Each groove contains equidistantly spaced diamond cutters along its length. The cutters are additionally oriented at a negative rake angle with respect to a borehole bottom. The vertical alignment of the diamond cutters paralleling an axis of the bit are staggered to destroy kerfs which remain in the formation from preceding eroded rows of diamond cutters as the bit works in the borehole."
U.S. Pat. No. 5,147,001 discloses "a cutting structure for earth boring drill bits and a bit including at least one such structure comprising a substantially planar array of cutting elements arranged in substantially contiguous mutual proximity, the array incorporating at least one discontinuity therein dividing it into a plurality of sub-arrays."
U.S. Pat. No. 5,238,074 discloses "[a] cutter for a rotating drag bit which has a cutting face formed from a plurality of polycrystalline diamond compact (PCD) elements. The elements can be of varying thickness and/or varying hardness to provide a cutting edge having a nonuniform wear pattern. Also provided is a cutter which includes two layers of PCD elements. The PCD elements can be of varying thickness and/or hardness to provide a cutter which presents a cutting edge having a wear ratio which varies with cutter wear. Also provided is an impact cutter having a cutting surface formed from one or more layers of PCD elements."
U.S. Pat. No. 5,551,522 discloses "A fixed cutter drill bit includes a cutting structure having radially-spaced sets of cutter elements. The cutter element sets preferably overlap in rotated profile and include at least one low profile cutter element and at least two high profile elements. The low profile element is mounted so as to have a relatively low exposure height. The high profile elements are mounted at exposure heights that are greater than the exposure height of the low profile element, and are radially spaced from the low profile element on the bit face. The high profile elements may be mounted at the same radial position but at differing exposure heights, or may be mounted at the same exposure heights but at different radial positions relative to the bit axis. Providing this arrangement of low and high profile cutter elements tends to increase the bit's ability to resist vibration and provides an aggressive cutting structure, even after significant wear has occurred."
U.S. Pat. No. 5,816,346 discloses "[a] rotary drill bit for drilling subsurface formations comprises a bit body having a shank for connection to a drill string, a plurality of primary blades and at least one secondary blade circumferentially spaced and extending outwardly away from a central axis of rotation of the bit, a plurality of cutters mounted along each blade, a majority of the cutters mounted on each of the primary blades having a greater exposure than a majority of the cutters on the secondary blade, and a sweep angle of the secondary blade is less than a sweep angle of the primary blades. The drill bit will exhibit a rate-of-penetration as a function of the size of the cutters on the primary blades, and exhibit a torque profile as a function of the size of the cutters on the at least one secondary blade."
U.S. Pat. No. 5,957,227 discloses "[a] drilling tool has several blades 16 each defining an outside wall 20 and two side walls 22, 24. The blades are separated by recesses 18, primary bits 28 are located along the outside wall of the blades, and secondary or backup bits 40 are attached behind the primary bits in relation to the direction of travel (f) of the tool. Each of the blades defines at least one divergent tunnel or channel 30 having small entry opening 32 located in the outside wall of the blade, behind the primary bits, and a larger exit opening 34 located on the rear side of the blade. The secondary bits are mounted at the rear edge of the entry opening, and the channel serves to discharge material excavated by them."
U.S. Pat. No. 5,979,571 discloses "[a] combination metal milling and earth drilling tool, for use in performing a single trip kickoff from a casing in a well bore. The combination milling and drilling tool has a first, relatively more durable cutting structure, such as tungsten carbide, and a second, relatively harder cutting structure, such as polycrystalline diamond. The more durable first cutting structure is better suited for milling metal casing, while the harder second cutting structure is better suited for drilling through a subterranean formation, especially a rock formation. The first cutting structure is positioned outwardly relative to the second cutting structure, so that the first cutting structure will mill through the metal casing while shielding the second cutting structure from contact with the casing. The first cutting structure can wear away while milling through the casing and upon initial contact with the rock formation, thereby exposing the second cutting structure to contact with the rock formation. The second cutting structure can then be used to drill through the rock formation."
U.S. Pat. No. 5,992,549 discloses "[a] cutting structure for a rotary drag-type drill bit includes a preform cutting element mounted on a carrier which, in use, is mounted on the drill bit and comprises a front facing table of superhard material bonded to a less hard substrate. A portion of the carrier on which the preform cutting element is mounted is shaped, adjacent the cutting element, for engagement by a chip of formation material being removed by the cutting element from the formation being drilled so as to tend to break the chip away from the surface of the formation. A portion of the carrier, or a portion of the bit body itself, may also be shaped, adjacent the cutting element, to direct to a location in front of the cutting element a flow of drilling fluid which impinges on said surface so as to assist in chip removal."
U.S. Pat. No. 6,283,233 discloses "[a] drill and/or core tool, in particular for oil drilling and/or coring, comprising a body (2) showing a substantially cylindrical peripheral surface (3) and a front (4), blades (5) which extend from the front (4) till over the peripheral surface (3) and which show each a leading edge (6), possibly PDC cutting elements (7) which are situated at least in a central area (15A) of the front (4) and the longitudinal axes of which are transverse to the rotation axis of the tool (1), and comprising moreover, on at least one blade (5), outside said central area (15A): PDC (7C) and/or secondary (10) cutting elements which show each a cutting edge (8), forming together the leading edge (6) of the blade (5), and the longitudinal axis of which is transverse to the rotation axis, and at least one associated cutting element (10A) which is situated behind at least one of the PDC (7C) or secondary (10) cutting elements, which shows a cross-section of the same shape, at least for its portion protruding from the blade (5), than that of the PDC (7C) or secondary (10) cutting element, and which is disposed on the same blade (5)."
U.S. Pat. No. 6,328,117 discloses "[a] chip breaker for use in a fixed-cutter, rotary-type drill bit used in drilling subterranean formations is disclosed. The chip breaker includes a knife-like protrusion positioned proximate a cutting element and adjacent or in a fluid course defined by the drill bit body. As formation chips, shavings, or cuttings are generated during drilling, the chips move over the protrusion and are split or scribed by the protrusion. Drilling fluid breaks the split or scribed chips away from the surface of the fluid course adjacent the cutting element and transports them through the junk slots. Additionally, chip splitters may be positioned on ramped surfaces that further lift the formation chips away from the surface of the fluid course."
U.S. Pat. No. 6,408,958 discloses "[a] cutting assembly comprised of first and second superabrasive cutting elements including at least one rotationally leading cutting element having a cutting face oriented generally in a direction of intended rotation of a bit on which the assembly is mounted to cut a subterranean formation with a cutting edge at an outer periphery of the cutting face, and a rotationally trailing cutting element oriented substantially transverse to the direction of intended bit rotation and including a relatively thick superabrasive table configured to cut the formation with a cutting edge located between a beveled surface at the side of the superabrasive table and an end face thereof. A rotationally trailing cutting element may be associated with and disposed at a location on the bit at least partially laterally intermediate locations of two rotationally leading cutting elements. Drill bits equipped with the cutting assembly are also disclosed."
U.S. Pat. No. 6,883,623 discloses "[a] rotary drill bit for drilling subterranean formations configured with at least one protective structure proximate to the rotationally leading and trailing edges of a gage trimmer, wherein the at least one protective structure is positioned at substantially the same exposure as its associated gage trimmer. Particularly, the apparatus of the present invention may provide protection for gage trimmers during drilling, tripping, and/or rotation within a casing; i.e., when changing a drilling fluid. Protective structures may be configured and located according to anticipated drilling conditions including helix angles. In addition, a protective structure may be proximate to more than one gage trimmer while having a substantially equal exposure to each associated gage trimmer. Methods of use and a method of rotary bit design are also disclosed."
U.S. Pat. No. 7,025,156 discloses "[a] rotary drill bit is used both for milling a casing window and drilling a lateral borehole into subterranean earthen materials, without the prior need of having separate drill bits for milling of the casing and for drilling of the borehole. The rotary drill bit is lowered into a casing set within a borehole; and the drill bit is rotated to engage an inner surface of the casing. A first set of cutting elements on the drill bit remove casing material to mill a casing window. The drill bit is then moved through the casing window so that a second set of cutting elements on the drill bit create a lateral wellbore in subterranean earthen material."
U.S. Pat. No. 7,048,081 discloses "[a] superabrasive cutting element for use with a drill bit for drilling subterranean formations and having a superabrasive table, or cutting face, in which a conglomerate of superabrasive particles is dispersed and bonded, or sintered, and in which at least one exposed cutting region of the superabrasive table develops a rough, asperital surface for improving the cutting efficiency of the drill bit, particularly in but not limited to relatively hard, relatively nonabrasive formations. The superabrasive table may include superabrasive particles of substantially differing size, or quality or a combination of differing size and quality. A rotary drill bit including cutting elements embodying the present invention is also disclosed."
U.S. Pat. No. 7,237,628 discloses "a drill bit with non-cutting erosion resistant inserts. In one illustrative embodiment, the apparatus comprises a matrix drill bit body comprising a plurality of blades, a plurality of cutting elements positioned on each of the blades, the cutting elements defining a plurality of web regions, and a plurality of spaced apart, non-cutting erosion resistant inserts positioned along a face of at least one of the blades, at least a portion of each of the non-cutting erosion resistant inserts being positioned in front of one of the web regions."
U.S. Pat. No. 7,278,499 discloses "[a] rotary drag bit including an inverted cone geometry proximate the longitudinal axis thereof is disclosed. The inverted cone region may include a central region, the central region including a plurality of cutting structures affixed thereto and arranged along at least one spiral path. The at least one spiral path may encircle its center of revolution at least once within the inverted cone region. A cone region displacement and a method for manufacturing a rotary drag bit therewith are disclosed. At least one groove may be formed within the cone region displacement along a respective at least one spiral path, the at least one spiral path encircling its center of revolution at least once. A plurality of cutting structures may be placed within the at least one groove and the cone region displacement may be placed within a mold for filling with an infiltratable powder and infiltrating with a hardenable infiltrant."
U.S. Patent Application No. 20070261890 discloses "[a] drill bit for drilling a borehole in earthen formations. In an embodiment, the bit comprises a bit body having a bit face comprising a cone region, a shoulder region, and a gage region. In addition, the bit comprises at least one primary blade disposed on the bit face, wherein the at least one primary blade extends into the cone region. Further, the bit comprises a plurality of primary cutter elements mounted on the at least one primary blade in the cone region. Still further, the bit comprises a plurality of backup cutter elements mounted on the at least one primary blade in the cone region, wherein the at least one primary blade has a cone backup cutter density and a shoulder backup cutter density, and wherein the cone backup cutter density of the at least one primary blade is greater than the shoulder backup cutter density of the at least one primary blade."
The inventions disclosed and taught herein are directed to an improved drill bit with continuously sharp cutting elements.

Drill bit with continuously sharp edge cutting elements