MXPA98009811A - Mouse with eye viewing for computac system - Google Patents

Abstract

The present invention relates to an optical mouse reflected as a series of pixels the spatial characteristics generally of any microtextured or microdetailed work surface below the mouse. The responses of the photodetector are digitized and stored produces successive frames of transferred patterns of pixel information, which are compared by autocorrelation to check the direction and the amount of movement. A retention feature suspends the production of motion signals to the computer, allowing the mouse to be physically placed back on the work surface without altering the position on the pointer screen. This may be necessary if the operator operates outside the room to physically move to move the mouse further, but the screen pointer needs to go further. The retention feature can be implemented with a current button, a separate proximity detector or detecting the presence of a characteristic condition in the digitized data, such as loss of correlation or overspeed of a selected limit. A convenient place for a current hold button is along the sides near the mouse button, where the opposite thumb and ring finger hold the mouse. The clamping force used to lift the mouse engages with the retention function. Retention can incorporate a short delay either by releasing the retention button, detecting the proper proximity or returning reasonable digitized values. During the delay, any lighting control or AGC server stabilizes the cycle. A new reference frame is taken before the resumption of movement detection

Description

MOUSE WITH "LOOKING EYE" FOR COMPUTER SYSTEM Reference to Related Patents This application is related to the subject matter described in the two U.S. Patents. following 5,578,812 filed on March 2, 1995, issued on November 26, 1996 and entitled HANDS-FREE PICTURE EXPLORER DEVICE COMPRISING THE NON-LINEAR MOVEMENT; and 5,644,139, filed on August 14, 1996, issued on July 1, 1997 and entitled NAVIGATION TO DETECT THE MOVEMENT OF NAVIGATION SENSORS RELATING TO DN OBJECT. Both of these patents have the same inventors: Ross R. Alien, David Beard, Mark T. Smith and Barclay J. Tullis, and both are assigned to Hewlett-Packard Co. This application is also related to the subject matter described in the Patent of the USA < currently unknown - S / N 08 / 540,355 authorized however not yet issued > filed on October 6, 1995, entitled METHOD AND SYSTEM FOR POSITION FOLLOWING, and also assigned to Hewlett-Packard Co. These three patents describe movement tracking techniques. These techniques are a component in the preferred embodiment described below. Accordingly, U.S. Patent Nos. 5,578,813, 5,644,139 and < any S / N Application 08 / 540,335 issued) are hereby incorporated by reference.

BACKGROUND OF THE INVENTION The use of a hand-operated pointing device for use with a computer and its monitor has become almost universal. With many of the most popular of the various devices is the conventional (mechanical) mouse. A conventional mouse typically has a lower surface that carries three or more pads projecting downward from a low friction material that raises the bottom surface a small distance on the working surface of a mat cooperating with the mouse. Located centrally within the lower surface of the mouse is a hole through which a portion of the underside of a steel ball coated with rubber (later called simply a rubber sphere) extends; during operation gravity pulls the sphere down and against the upper surface of the mouse mat. The mouse mat is usually a closed cell foam mat covered with a suitable fabric. The low-friction pads slide easily on the fabric, but the rubber sphere does not slip, but instead it rolls as the mouse is moved. Inside the mouse are rollers, or wheels that make contact with the sphere at its equator (the large circle is parallel to the bottom surface of the mouse) and converts its rotation into electrical signals. The external mouse housing is configured so that when it is covered by the user's hand it appears to have a "front to back" axis (along the user's forearm) and an orthogonal "left to right" axis. The inner wheels that make contact with the equator of the sphere are arranged so that a wheel responds only to the rolling of the sphere that results from a component of movement of the mouse that is along the axis from front to back, and also from so that the other wheel responds only to a roll produced by a component of movement along the axis from left to right. The resulting rotations of the contact wheels or rollers produce electrical signals representing these movement components. (Let's say, F / B represent front and back, and L / R represents left or right). These electrical signals F / B and L / R are coupled to the computer, where the software responds to the signals to change by a Deltax and a Delta and the presented position of a pointer (cursor) according to the movement of the mouse. The user moves the mouse as necessary to obtain the pointer presented in a desired location or position. Once the pointer on the screen points to an object or location of interest, one of one or more buttons on the mouse is activated with the fingers of the hand that holds the mouse. The activation serves as an instruction to take some action, the nature of which is defined by the software on the computer. Unfortunately, the usual classification of the mouse described above is subject to a number of drawbacks. These include the deterioration of the mouse's sphere or damage to its surface, deterioration or damage to the surface of the mouse mat, and the degradation of the ease of rotation of the contact rollers (say, (a) due to the accumulation of dirt or lint, or (b) due to wear, or (c) both (a) and (b)). All these things can contribute to the total or erratic failure of the mouse to work as necessary. These episodes can be quite frustrating for the user, whose complaint could be that while the cursor on the screen moves in all other directions, it can not get the cursor to say it moves down. Consequently, the industry has responded by making the mouse sphere removable for easy replacement and for cleaning the recessed region in which it fits. Increased mouse sphere hygiene was also a major motivation in the introduction of mouse mats. Regardless, some users are extremely dissatisfied with their particular mouse movement when these resources appear to be unavailable. The replacement of the mouse and the mouse mat is an active business. The outstanding reason for all this problem is that the conventional mouse is largely mechanical in its construction and operation, and depends on an important degree on a rather delicate compromise about how the mechanical forces are developed and transferred. Several attempts have been made before to use optical methods to replace the mechanical parts. These have included the use of photodetectors that respond to mouse movement on specially marked mouse mats, and respond to the movement of an especially separate mouse sphere. The U.S. Patent 4,799,055 describes an optical mouse that does not require any specially marked surface previously. (Describes two broad linear arrays of an orthogonal pixel of light sensors in the X and Y directions and their machine state motion detection mechanism initially made by a distant cousin of the Embedded Patents technique, although it is our approach that the arrangement shifted and correlated with [pixel pattern within an area] the technique of the incorporated patents is considerably more sophisticated and robust). To date, and despite decades of user frustration with the mechanical mouse, none of these prior optical techniques has been widely accepted as a satisfactory substitution for the conventional mechanical mouse. In this way, it would be desirable if there were a non-mechanical mouse that was viable from a manufacturing perspective, relatively cheap, reliable and that would appear to the user essentially as the operational equivalent of the conventional mouse. This need can be met by a new type of optical mouse that has a familiar "touch" and is free from unexpected behavior. It would be even better if the operation of this new optical mouse does not depend on the cooperation of a mouse mat, if it is special or different, but instead it is able to navigate almost any arbitrary surface. SUMMARY OF THE INVENTION One solution to the problem of replacing a conventional mechanical mouse with an optical counterpart is to optically detect the movement by forming images directly according to a pixel array of the various spatial characteristics of a work surface under the mouse , as much as it is believed that human vision does. In general, this work surface can be any almost flat surface; in particular, the work surface does not need a mouse mat, special or otherwise. For this purpose, the work surface below the image forming mechanism is illuminated from the side, say with an infrared (IR) light emitting diode (LED). Surprisingly a wide variety of surfaces creates a rich collection of highlights and shadows when illuminated at an appropriate angle of incidence. This angle is generally low, say, in the order of five to twenty degrees, and will end at an angle of "rub" incidence. Paper, wood, and painted surfaces work well; about the only surface that does not work is smooth glass. { unless it is covered with printed fingers;). The reason why these work surfaces have a macro texture is that in some cases it can not be perceived by the human senses without help. The infrared light reflected from the microtextured surface is focused on a suitable arrangement (say, 16 X 16 or 24 X 24) of photodetectors. The light emitting diode can be either continuously or with a stable or variable amount of illumination served to maximize some aspect of operation (v.gr, the dynamic range of the photodetectors in conjunction with the albedo of the work surface) . Alternatively, a charge accumulation mechanism coupled to the photodetectors can be "sealed" (by current diverting switches) and the LED is pulsed on and off to control the service exposure of the average amount of light. Returning to the LED when switching it off also saves energy; an important consideration in battery operated environments. The response of the individual photodetectors are digitized at an appropriate resolution (say, six or eight bits) and stored as a frame in the corresponding locations within a memory array. Having in this way the given mouse an "eye", we form an additional equipment to "see" the movement by means of comparisons of operation with the successive frames. Preferably, the size of the image projected on the photodetectors is a slight amplification of the original characteristics that will be reflected, say, two to four times. However, if the photodetectors are small enough it may be possible and desirable to provide them with an amplification. The size of the photodetectors and their spacing is such that it is much more likely that they are one or several adjacent photodetectors with reflective characteristic, rather than otherwise in their skid. In this way, the pixel size represented by the individual photodetectors corresponds to a spatial region on the work surface of a size that is generally smaller than the size of a typical spatial feature on the work surface, which may be a strand of fiber in a cloth that covers a mouse mat, a fiber in a piece of paper or cardboard, a microscopic variation in a painted surface, or an element of an embossed microtexture or a plastic laminate. The overall size of the arrangement of the photodetectors is preferably large enough to receive images of various characteristics. In this form, the images of said spatial characteristics produce translated patterns of pixel information as the mouse moves. The number of photodetectors in the array and the speed of the frame in which their contents are digitized and captured cooperate to influence the speed according to the sighted eye of the mouse that can be moved on the work surface and still be followed. Tracking is achieved by comparing a newly captured sample box with a previously captured reference frame to check the direction and amount of movement. One way that can be done is by changing the total content of one of the frames by a distance of one pixel (corresponds to a photodetector), successively in each of the eight directions allowed by a change of pixel deviation test (on one, on one, and below one, below one, above one, above one and above one, above one in the other direction , etc.). This adds eight tests, but we must not forget that there can be no movement, thus a ninth "zero change" test is also required. After each test, those parts of the frames that overlap one another are subtracted on a pixel per pixel basis, and the resulting differences are added (and then preferably squared) to form a measure in the same way (correlation) ) within the overlap region. Of course changes are possible in the larger test, (eg over two and under one), but at some point the concomitant complexity ruins the ntage, and it is preferable that it simply has a sufficiently high frame rate with small changes test. The test change with the minor difference (major correlation) can be taken as an indication of the movement between the two frames. That is, it provides a raw F / B and L / R. The raw movement information may be scaled and / or accumulated to provide information on the movement of the display pointer (Deltax and Deltay) of a convenient granularity and an adequate rate of information exchange. The current algorithms described in the incorporated patents (and used with the sighted eye mouse) are refined and sophisticated versions of those previously described. For example, it allows us to say that the photodetectors were of an arrangement of 16 X 16. We can say that initially we will take a reference frame by storage of the digitized values of the outputs of the photodetector as they appear sometime in TQ. At some later time we take a sample box and store another series of digitized values. It is desired to correlate a new collection of nine comparison tables (it is thought to be null, on one, on one and on top of one, etc.) against a version of the reference frame that represents "where you were last time". Comparison tables are temporarily changed versions of the sample box; Note that when a comparison table is changed, it will not overlap the table reference exactly. One edge, or two adjacent edges, will be unequal, as they were. The pixel locations along the mismatched edges will not contribute to the corresponding correlation (that is, to the particular change), but all the others will do so. And those others are a substantial number of pixels, which give rise to a very good radio interference signal. During the "near-neighborhood" operation (that is, limited to null, on one, one above / below one, and their combinations), the correlation produces nine "correlation values", which can be derived from a sum of square differences for all pixel locations that have spatial correspondence (that is, a pixel location in a frame that is in effect paired with a pixel location in the other frame - the mismatched edges will not have such pairing).

A short note is perhaps in order about how the change is made and the correlation values obtained. The change is achieved by directing offsets to the memories that can produce an entire row or column of an array at a time. The dedicated arithmetic circuitry is connected to the array of the memory that contains the reference frame that is changed and to the array of the memory that contains the sample box. The formulation of the correlation value for a particular test change (member of the collection closest or closest to the neighborhood) is achieved very quickly. The best mechanical analogy is to reflect a transparent film (reference) of light and dark patterns arranged as if they were a checker board, except that the arrangement may be random. Now imagine that a second movie (sample) has the same general pattern overlaid on the first, except that it is the negative image (dark and clear are exchanged). Now the pair is aligned and kept in light. As the reference film is moved relative to the film it shows the amount of light admitted through the combination will vary according to the degree to which the images match. The positioning that admits the minor light is the best correlation. If the negative image pattern of the reference film is a frame or two displaced from the image of the sample film, the positioning that the smaller light admits will be the one that coincides with the displacement. It is noted which displacement admits less light; with the sighted eye mouse we observe the positioning with the best correlation and we say that the mouse moves too much. So in effect, what happens is inside an integrated circuit (Cl) that has photodetectors, memory and arithmetic circuits arranged to implement the image correlation and the tracking technique that we are describing. It would be desirable if a given reference frame could be re-used with successive sample frames. At the same time, each new collection of nine (or twenty-five) correlation values (for collections in t¿, t ^ + tL etc.) that originate from a new image in the photodetectors (a sample box below) should contain a satisfactory correlation. For a hand-held mouse, the various successive collections of comparison tables can usually be obtained from the reference frame (16 X 16) taken at t0. What is allowed to do is keep the direction and displacement of the most recent movement data (which is equivalent to the known speed and the interval from the previous measurement). This allows the "prediction" of how to change (permanently) the collection of pixels in the reference frame so that for the next sample box a "near neighborhood" can be assumed to be correlated. This change that accommodates the prediction throws, or removes, some of the references in the table, reducing the size of the reference frame and degrading the statistical quality of the correlations. When a border of the changed and reduced reference frame begins to approach the center of what was the original reference frame it is time to take a new reference frame. This way of operation is called "prediction" and can also be used with comparison tables that are 5 X 5 and a "close neighborhood" of extended algorithm (null, on two / above one, on one / above two, on one / above one, about two, about one, ...). The prediction benefits are an overspeed of the tracking pss through the online internal stream correlation pdure (avoiding the comparison of two arbitrarily related 16 X 16 data arrays) and a reduction in the percentage of time spent acquiring tables of reference. In addition to the usual buttons that a mouse usually has, the sighted eye mouse may have another button that suspends the production of motion signals to the computer, allowing the mouse to be physically relocated on the work surface without altering the position on the pointer screen. This may be necessary if the operator works outside the room to physically move the mouse additionally, but the screen pointer still needs to go further. This can happen, say, in a UNIX system that employs a presentation system known as "Simple Logical Screen" where perhaps as many as four monitors are arranged for each sub-portion of a monitor of the entire "screen". If these monitors were arranged as one high by four interns, then the distance from left to right necessary for a simple corresponding maximum mouse movement could be much wider than usually allowed. The usual maneuver executed by the operator, say, an extended excursion to the right, is simply to pick up the mouse on the right side of the work surface (a mouse mat, or perhaps the edge simply of clearing on an otherwise disordered surface). from your desk), arranged down to the left and continues moving to the right. What is necessary is a way to maintain the movement that indicates the signals of false behavior that is experienced during this maneuver, so that the pointer on the screen behaves in a non obvious and assumed way. The function of the "hold" button can be performed automatically by a sensor near the bottom of the mouse that determines that the mouse is not in contact with the work surface, or by the observation that all or a majority of the pixels in the image they have "gone dark" (this is currently a bit more complicated than that - we will say more about this idea in the next paragraph). Without a retention feature, the image may have some slight tilt during the removal and replacement of the mouse, which is either: (a) at a tilt of the field of view as the mouse is raised; or (b) some perverse error where the frames for two widely separated and disparate spatial characteristics are seen at very different times during the removal and substitution taken independently as they represent a small distance between two frames with the same characteristic. A convenient place for a real hold button is located along the side parts of the mouse near the bottom, where the thumb and ring finger opposing will hold the mouse to lift it. A natural increase in clamping force used to lift the mouse would also mesh with the hold function. A retention feature can incorporate a brief optional delay by any release of the retention button, appropriate proximity detection or the return of reasonable digitized values. During that delay any lighting control of server cycles or internal automatic gain controls would have time to stabilize and a new reference frame could be taken before the resumption of motion detection. And now for the matter of which the pixels in the image "go dark", what happens, of course, is that the infrared light of the LED of illumination does not arrive more to the photodetectors in the same quantity that suits him, yes in all; The reflecting surface is also quite far away or simply not visible. However, if the sighted eye mouse is flipped, or the lower part is exposed to a strong light environment as a result of being raised, then the outputs of the photodetectors may be at any level. The key is that they will be uniform, or in this way closely. The main reason that it becomes uniform is that the focused image is not larger; all the characteristics of the image are indistinct and each one is disseminated over the entire collection of photodetectors. So the photodetectors enter uniformly at some average level. This has a different contrast in the case when the image is focused. In the case of focused correlations between the tables (it is called the envelope one, on one and below one, etc.) exhibit a different phenomenon. It is assumed that the spatial characteristics are followed exactly by the mapping on the photodetectors, through the lens system, and that the movement of the mouse was unequal but exactly the amount and in the directions necessary for a characteristic that goes from detector to detector. Now for simplicity it is also assumed that there is only one feature, and that its image is the size of a photodetector. In this way, all photodetectors, however, are all very important at the same level, and the detector that is not at that level is at a substantially different level, presenting the characteristic. Under these highly idealized conditions it is clear that the correlations will behave very well; eight "large" differences and a small difference (a countersunk hole in a quite flat surface) in a system that uses nine tests for a closely neighboring algorithm (and remembering that it could not have been removed). [Note: The clever reader will report that the "big" difference in this rather artificial example currently corresponds to, call back or originate only one pixel that probably does not deserve to be called "big" - with the analogy of the movie changed before. The only light that passes through the movies in this example would be for the unique pixel of the feature.

A more normal image that has a considerably more diverse collection of pixels increases the difference where there really is a "big" difference. ] - Now, such highly idealized conditions are not the usual case. It is more normal for the image of the spatial characteristics followed to be both larger and smaller than the size of the photodetectors, and that the movement of the mouse is continuous, following a trajectory that allows the images to fall on more than one detector at a time. time. Some of the detectors will only receive a partial image, which means that some detectors will make an analogous addition of both light and dark. The result is at least a "widening" of the countersunk hole (in terms of the number of photodetectors associated with it) and quite possibly a corresponding decrease in the depth of the countersunk hole. The situation can be suggested by the rolling of the heavy image-forming sphere along a tense but very stretchable membrane. The membrane has a discrete whole Cartesian coordinate system associated with it. How many membranes are distended in any location of the integral coordinate as the sphere rolls? Imagine first that the sphere is of a very small but very heavy diameter, and then imagine that the sphere is of a large diameter, but still weighs the same. The analogy can not be exact, however this serves to illustrate the idea of the "countersunk hole" mentioned before. The general case is that the generally flat surface with the countersunk hole clearly defined forms a broad concavity, or bowl.

The surface produced or described by the various correlation values of the "correlation surface" will be graded and, at various times, the configuration of that surface will be more interesting. All this is said to carry out two points.

First, the shape of the concavity changes in the correlation surface as the sighted eye mouse moves allowing interpolation to a granularity finer than the simple size / spacing of the photodetectors. We point out this discarded, with the observation that our mouse with a sighted eye can do it, and stop doing it. The complete interpolation details are described in the incorporated patents. No other discussion of interpolation is considered necessary. Second, and this is our real reason for the discussion of the preceding paragraphs, is the observation that what happens when the sighted eye mouse is raised so that the concavity on the correlation surface disappears, to be replaced by values for the generally equal correlations (ie, a "flat" correlation surface). It is when this happens that we can say with considerable security that the sighted eye mouse is held in the air, and then it can automatically invoke the retention feature, until after that moment when the appropriate concavity reappears ("bowl").

Another method for invoking or initiating a retention feature is simply to warn that the sighted eye mouse is moving faster than a certain threshold velocity (and thus presumably is experiencing an abrupt retracement movement in a intended maneuver to move the screen mouse farther than the available physical space within which the mouse is operating). Once the threshold velocity is exceeded, the signals indicating the movement that would otherwise be associated with that movement are suppressed until said moment when the velocity drops below a suitable level. Brief Description of the Drawings Figure 1 is a side view in simplified pictographic section of a navigation and imaging arrangement of the prior art; Figure 2 is a bottom view of a mouse constructed in accordance with the invention; Figure 3 is a side perspective view of a mouse constructed in accordance with an aspect of the invention; Figure 4 is a simplified side sectional view of a sensor near the base of the mouse of Figures 2 and 3 and used, to automatically activate a retention feature; Figure 5 is a simplified flow chart describing an aspect of the operation of the mouse with internal seer eye related to the function of the retention feature when used in conjunction with a feature called prediction; Figure 6 is a simplified portion of a modification of the flow diagram of Figure 5 and illustrates the speed detection method of invoking the retention feature; and Figure 7 is a perspective view of a graphed correlation surface having good concavity. Description of a Preferred Modality Referring now to Figure 1, wherein a simplified representation of a sectional side view of an array of image and navigation 1 of the prior art is shown which is generally of the type described by the Patents incorporated. An LED 2, which can be an IR LED, emits light that is projected by the lens 3. { which instead of being separated can be an integral part of the LED package), through the hole 13 in the lower surface 6 and in a region 4 that is part of a working surface 5. The average angle of incidence is preferably within of the range of five to twenty degrees. Although it has been omitted for clarity, the hole 13 may include a window that is transparent to the light of LED 2, and which would serve to leave dust, dirt or other contaminants out of the entrails of the mouse with sighted eye. The work surface 5 may belong to a special object, such as a mouse mat, or more generally, it will not be and can not be the surface of anything close except plain glass. Examples of suitable materials included, but not limited to, paper, cloth, laminated plastic covers, painted surfaces, frosted glass (smooth side bottom, serves), desk mats, real wood, simulated wood, etc. Generally, it will be made of any microtextured surface that has characteristics whose size falls within the range of 5 to 500 microns. Illumination of microtextured surfaces is most effective when done from the side, as this accentuates the patterns of highlighting and shading produced by high irregularities of the surface. Appropriate angles for illumination cover the range of approximately five to twenty degrees. A very uniform or flat surface (eg, one that has been ground and polished) also has simple variations that are due to the reflectivity of (micro scale) compositional variation of performance. In such a case (and assuming that it can be guaranteed) the angle of incidence for the illumination can approach ninety degrees, since the impulse to create shadows disappears. However, such a uniformly microdetailed surface is one in which we could not ordinarily think of when we say "arbitrary surface", and we intend to use a sighted eye mouse on an "arbitrary surface" that is most likely microtextured where it would work best if It is equipped to provide a friction angle of incident lighting. An illuminated region 4 of the image is projected through an optical window 9 into a bundle portion 8a of an integrated circuit and into a array 10 of photodetectors. This is done with the aid of the lens 7. The package portion 8a can also be dispensed with the separate window 9 and the lens 7 by combining them with the same window and with the same element. The photodetectors may comprise a square arrangement of, say, 12 to 24 detectors on one side, each detector being a phototransistor whose light-sensitive region is 45 by 45 microns and 60 microns with center-to-center spacing. The capacitors charge phototransistors whose voltages are digitized and subsequently stored in a memory. The array 10 is fabricated in a portion of an integrated circuit die 12 fixed by an adhesive 11 on the package portion 8b. That none of the details of how the integrated circuit is retained in place (probably by a printed circuit board), the configuration or composition of the lenses, or how the lenses are mounted are shown.; It is clear that those things are feasible in a conventional way. It is also clear that the general level of illumination of region 4 can be controlled by observing the output levels of the photodetectors and adjusting the intensity of the light emission from LED 2. This can be any continuous control width modulation or impulse, or some combination of both. Again, the reader recalls that the details of the motion perception operation are fully described in the patents incorporated (and briefly described in the Compendium); consequently, they do not need to be repeated here. Referring now to Figure 2, which is a bottom view of a mouse 14 constructed in accordance with the invention. In summary, this bottom view of this particular sighted eye mouse 14 looks very similar to the bottom view of a particular conventional mouse from Hewlett-Packard Co., namely: C1413A. The main difference is that where a sphere can be there is a protective lens or window 16 that is transparent to IR light. This is the transparent window omitted in the hole 13 that was mentioned in the description of Figure 1. Also what is missing is the usual rotating ring that serves as a removable retainer to allow access to the sphere for cleaning or replacement. What is shown in the figure is the lower side part 15 of the mouse 14 (corresponds to 6 in Figure 1), the low friction slides 19 and the connector cable 17 with its stress relief 18. Of course, the mouse with Sighting eye 14 can be a cordless mouse, as well as, with a radio communication or optical link for the computer. Referring now to Figure 3, where a side perspective view of a mouse 14 constructed in accordance with an aspect of the invention is shown. The aspect of the invention is the retention characteristic. The retention feature is an aspect of the operation of the sighted mouse that suspends the production of information or signals of movement to the computer when it is determined that the mouse is not adequately close to the work surface whose spatial characteristics will be followed. This allows the sighted eye mouse to be lifted, moved and stopped down, or, since that operation was concluded, it is "cleaned" through the work surface. In particular, the sighted eye mouse 14 of Figure 3 includes at least one retention button 24 located in the side skirt 2 near the lower surface 15 so that it is below the right thumb or the left ring finger, depending on what hand the operator is using. Another symmetrically located button may be on the other side (not illustrated) that would contact either the left or the right ring finger. The mouse 14 conventionally includes a surface 21 that is nested in the palm of the hand and in the first and second buttons 22 and 23 of the "regular" mouse that are operated by the index and middle fingers. These operate in their normal form. The button or buttons 24 are activated by a natural increase in the clamping force required to lift the mouse 14 during cleaning. When one or both of these buttons are pressed the hold feature is activated. As for the duration of retention the sending of signals of movement to the computer is suspended. When the retention is over (the buttons are released) a new reference frame is taken before any of the new motion signals that are sent to the computer. This allows cleaning, and has the advantage that the user has the ability to expressly force the ignition of the holding feature. The retention feature can also be activated automatically by the action of a separate proximity sensor on the bottom of the mouse. This is what is shown in Figure 4, where an aperture 26 supported in the base 6 receives a plunger pushed with the shoulder 25 made captive by the lever arm of a prior switch 28. The switch 28 is activated by the movement of the plunger 25, so that when the plunger moves significantly in the direction of the arrow 27 the holding characteristic is activated. The exact nature of the separate proximity sensor is a selection issue, and although it may be as simple as the microswitch 28 operated by the weight of the mouse through the plunger 25, other non-mechanical methods are possible. Yet another way to automatically activate and deactivate the retention feature is to examine the nature of the digitized data of array 10 of the photodetectors. When the outputs of the photo-detectors become sufficiently uniform, it can be assumed that there is no more an image with projected variations on the arrangement 10 of the photodetectors. This in itself will uniformly reveal the production of a correlation surface that is flat or closely planar. Instead of uniform levels being detected separately (which would otherwise use the hardware would not be present), it is preferred instead to examine the shape of the correlation surface, (whose surface is anyway needed for other reasons). The most likely cause of a flat correlation surface is that the mouse has been picked up. This mode of operation may require a fairly narrow depth of field, so that no undue delay occurs when activating the retainer. This delay can produce minor artifacts in the screen's movement pointer. This may include slight unintended screen mouse movements that are due to mouse inclination as it is either picked up or replaced. While the retention feature is activated (however, if it is done, manually or automatically) forces the acquisition of a new reference frame before resuming the production of motion signals, it should not be dangerous to produce a false indication that results of the combination of previous data with some new data that are only accidentally viewed as a small appropriate movement in some inappropriate direction. However, with the mere detection of uniform level (of, let's say, a picture shows) it can be difficult to guarantee that while it is moving in the air there are no optical effects (a reflection of a brightness source) that would confuse the algorithm. It will be appreciated that the configuration of the correlation surface is a much more reliable indicator. From all that has been said, it must still be remembered that the handling, as it was, of the screen pointer is a similar operation with a driver server incrementally performed by a human being; if the screen pointer is not yet, just keep moving the mouse as necessary! The small disturbances during cleaning are not fatal, and may not be particularly noticeable, depending on the specific application being made. Referring now to Figure 5, where a flow chart 29 is shown describing an aspect of the operation of the sighted eye mouse involving the retention and prediction properties. We can assume that there is some starting condition or location 30, from which you reach stage 31: ACQUIRE A REFERENCE BOX. This refers to the LED 2 that illuminates and stores a collection of digitized detector photo values in a memory order (not illustrated). The next step 32 is to ACQUIRE A SAMPLE PICTURE. This refers to the same actions, except that the data is stored in a different memory array, and may reflect the movement of the mouse relative to where it was when step 32 was carried out. In step 33, COMPUTA VALUES OF CORRELATION, the nine values of correlation (or perhaps twenty-five) are quickly computed by some arithmetic hardware duly dedicated heavy assisted by the automatic address transfer and a very broad trajectory of memory arrangements. In step 34, IS CORRELATION OF SURFACES ADEQUATELY CONCAVE ?, the nature of the correlation surface described by the collection of correlation values computed in step 33 is examined. We want to know if it is configured as a bowl, and if so, "how much water will it contain", so to speak. If the shape of the correlation surface is also bowl, path 36 takes step 37 optional: IS THE RETAIN BUTTON PRESSED ?; approximately more than in the next paragraph. Otherwise we have a flat correlation surface, or an "erroneous bowl", and proceeds along path 35 to an optional step 42, DELAY. There are several possible causes for this output of the qualifier 34: v.gr. extreme speed, work surface without sudden characterization, and, a mouse held to the air. In the absence of an explicit HOLD button, we will depend on the output path 35 to provide the proper behavior of the sighted eye mouse by suppressing motion signals to the computer during the cleaning operation of the air-holding part. If the sighted eye mouse has a hold button, then the optional qualifier 37 is present, and it is found that the state (depressed or not) of the RETENTION button 24 is determined. The case where this is pressed is treated the same as that for an erroneous bowl in a classifier 34. That is, path 38 is taken, which also leads to optional step 42. Optional step 42 provides a delay that may be useful in several ways. First, if a cleaning is in progress, then it takes some time, and there is no imaging during that time some of the battery power can be saved. Also, it is assumed that the nature of the delay is slightly more complex than a pause in the movement of a finger that moves on the flow chart. Assume that step 31 of ACQUIRING THE REFERENCE BOX was influenced by having been a delay in step 42, in that part the way through the delay of a lighting level control operation is initiated. This could allow the time to readjust the lighting levels, etc. If there is an optional one-step DELAY 42 or not, the path 43 returns to step 31, where another motion detection cycle begins. To summarize, the path 39 leads to step 40: PREDICT THE CHANGE IN THE REFERENCE BOX. As mentioned before, it is generally not necessary to obtain and maintain the current speeds in X and Y, and the interval information, to find the displacement necessary for the prediction. One can imagine the measurement environments where this may be necessary, but what is shown here is not one of them. Instead, the predicted change can be taken as the amount of movement corresponding to the correlation in the preceding step 34. The next step 44 PRODUCES DeltaX and Delta Y. It is here that it is noted how much the movement has been of the mouse from the last measurement cycle. The amount of change needed to obtain the correlation is the desired amount. These values can be found by observing which comparison chart is currently correlated (assuming no interpolation). These "gross" DeltaX and DeltaY movement values can be accumulated in operating values that are sent to the computer at a lower rate than that in which the raw values of step 44 are produced. In the qualifier 45 we ask if we NEED A NEW REFERENCE BOX ?. If the answer is YES, path 46 leads to step 48: STORE THE BOX SHOWS PRESENT IN THE REFERENCE BOX.

(A small point will confirm that this re-use of the chart shows cooperation without having to maintain the current speeds and time intervals for the prediction process.If we took a new separate reference frame it would complicate a number of things, and probably force the use of D = RT - that is, the distance formula - for the prediction). We need a new reference frame when it has been enough to change it, which is due to the predictions, that it is not enough to overlap the comparison tables for reliable correlations. Somewhere in the range of three to five changes (which does not rebuild them) is approximately the limit for a reference frame of 16 X 16. If the answer to rating 45 is NO, and we do not need to replace the reference frame, then the path 47 takes the same step 49 as it conducts the path of step 48. Step 49, CHANGES THE REFERENCE CHART, performs the current permanent change of the values in the memory array that represents the reference frame. The change is by the amount of prediction, and the changed data is lost. Following the change, the trajectory of the reference frame 50 returns to step 32, ACQUIRING A SAMPLE PICTURE, where the next measurement cycle begins. Referring now to Figure 6, where a simplified flow chart segment 50 is shown showing how to replace step 44 of flow chart 29 in Figure 5 with steps 51-55. The purpose for doing this is similar to the various ways of maintaining the operation already described, and it can be used in conjunction with it, or in its place. The general idea of the modification represented by Figure 6 is to confuse the output of the computer either without sending any updated information skipping step 55A or (optionally, with step 55B) that sends zeros for DeltaX and DeltaY, even though this does not it's true. This is done when step 52 checks that the rate of mouse movement exceeds, say, three to six inches per second. For a sighted eye mouse such a limit is easily expressed as a displacement by a certain number of pixels within some number of measurement cycles, assuming that the rate of the measurement cycle is compared quickly with the movement of the normal mouse. The idea is that probably the normal casual mouse movement will not require either a new neighbor neighbor reference frame (allows only a maximum change for a near neighbor operation of 5X5) each measurement cycle for some large number of measurement cycles consecutive (say, ten to twenty-five). As if this were the case, the sighted eye mouse could be operated over the hairy edge of the retention mode via a NO response to qualify 34 and trajectory 35. (In accordance with the assumption, any higher velocity will give as result the loss of correlation). That is, the expectation is that it takes a new reference frame normally much less frequent. Of course, it can happen that the mouse speed is really high, and the path 35 is used, in any form. This is how it should be. However, if the speed of the measurement cycle is not sufficiently high with respect to the expected normal mouse movement, then it may not be appropriate to use the technique of Figure 6. Step 51 represents anything from step 44 above about and around the actual communication to the computer of the DeltaX and DeltaY values. A difficult example of this difference may be an internal accumulation of movement that has not yet been dispatched to the computer, which is due to a measurement cycle speed of greater internal movement for the mouse with sighted eye than the regime of exchange of information with the computer. Now, it may also be the case that in some systems the accumulated information is used for the purposes of the internal mouse other than that strictly to maintain ^ 5 informed the computer. If so, I would need it to be preserved, for all this the qualifier 52, the trajectory 53 (and derived to step 55A) need to be able to say NO, the computer there has had movement; We want to cheat the computer but without causing the mouse to lose its memory. 2o So it will be notified if saccumulation was left to continue during a fast retracement, intended to simulate the mouse being picked up, the computer can still win at the end when the speed drops to normal amounts and the accumulation is finally sent; 5 the screen cursor can go to the correct location, in any way, depending on how the whole system works. In sa case a separate series of accumulations must be maintained, with those so that the computer remains derived to step 55A. Of course, it may be the case that there is no internal use for the accumulated DeltaX and DeltaY mouse, otherwise send it to the computer. In this case we need to make it different from the accumulation that derives to step 55A. It is also possible that the mouse does not have simple accumulations that cause these connections; let's say, any of those accumulations were made by the software on the computer. Finally, reference will now be made to Figure 7. There is a graph 56 of a correlation surface 57 near the neighborhood (5X5) having a suitable concavity. The two horizontal axes 58 and 59 represent the X and Y axes of the mouse movement; the units indicated along the axes are pixels. The drawing in the plane of axes 58 and 59 are uniform and interpolated contour lines 60 intended to further indicate the shape of the correlation surface directly above. The vertical axis 61 is a correlation measure expressed in essentially arbitrary units.

Claims (12)

1. A pointing device held by hand for a computer system or the like, the pointing device comprises: a housing having a flat bottom surface that moves against a work surface having reflective characteristics; the housing also has a top surface shaped to receive the human hand; the housing also has a skirt connecting a perimeter of the flat bottom with the top surface; the housing has a first axis extending generally in the direction where the heel of the hand rests on the upper surface where the middle finger rests on the upper surface, and a second axis perpendicular to the first, both axes being parallel to the lower surface; an opening in the lower surface; a light source mounted inside the housing, close to the opening and which illuminates the reflective characteristics on the work surface; an optical motion detection circuit mounted within the interior of the housing and close to the opening, the motion detection circuit produces motion indication signals indicative of movement in the directions along the first and second axes and in relation to the illuminated reflective characteristics visible through the aperture; and wherein the optical motion detection circuit comprises a plurality of photodetectors each having an output, a memory containing a reference frame of the output values of the digitized photodetector and a sample box of digitized photodetector output values obtained Subsequent to the reference frame, and further wherein a plurality of comparison tables each being a changed version of the reference frame, is correlated with the sample frame to check the movement in the directions along the first and second axes .

2. A device as in claim 1, wherein the existing reference frame is changed by an amount corresponding to the preceding correlation with a comparison table.

3. A device as in claim 1, wherein an existing sample frame is taken periodically as a new reference frame.

4. A pointing device held by hand for a computer system or the like, the pointing device comprises: a housing having a flat bottom surface that moves against a work surface having reflective characteristics; the housing also has a top surface shaped to receive the human hand; the housing also has a skirt that connects with a perimeter of the flat lower part with the upper surface; the housing has a first axis extending generally in the direction where the heel of the hand rests on the upper surface where the middle finger rests on the upper surface, and a second axis perpendicular to the first, both axes are parallel to the lower surface; an opening in the lower surface; a light source mounted inside the housing, close to the opening and which illuminates the reflective characteristics on the work surface; an optical motion detection circuit mounted within the housing interior and close to the opening, the motion detection circuit produces motion indication signals indicative of movement in the directions along the first and second axes and relative to the illuminated reflective features visible through the aperture; and a nearby detector that detects when the lower surface is outside the work surface by more than a selected distance, which is coupled to the optical motion detection circuit, and that inhibits the production of the motion indication signals when the surface bottom is off the work surface by more than the selected distance.

5. A device as in claim 4, wherein the proximity detector comprises at least one switch arranged on the skirt at a location below the right thumb or the left annular of a hand holding the pointing device.

6. A device as in claim 4, wherein the proximity detector comprises at least one switch disposed on the skirt at a location below the left thumb or right annular of a hand holding the pointing device.

A device as in claim 4, wherein the optical motion detection circuit comprises a plurality of photodetectors each having an output, a memory containing digitized photodetector output values and the proximity detector comprises arithmetic comparison circuits coupled to the values digitized in the memory.

8. A device as in claim 4, wherein the proximity detector comprises a pressure operated switch disposed proximate to the bottom surface.

A device as in claim 4, wherein the optical motion detection circuit comprises a plurality of photodetectors each having an output, a memory containing a reference frame of output values of the digitized photodetector and a comparison table of output values of the digitized photodetector obtained subsequent to the reference frame, and wherein a new reference frame and the subsequent comparison table are obtained with the conclusion of an inhibition of the production of motion indication signals and before a resumption of the production of motion indicator signs.

A device as in claim 9, wherein the new reference frame is obtained after a delay of a selected amount beyond the point in time when the proximity detector detects only the lower surface which is far from the work surface by the selected distance.

11. A pointing device held by hand for a computer system or the like, the pointing device comprises: a housing having a flat bottom surface that moves against a work surface having reflective characteristics; the housing also has a top surface shaped to receive the human hand; the housing also has a skirt connecting a perimeter of the flat bottom with the top surface; the housing has a first axis extending generally in the direction from where the heel of the hand rests on the upper surface where the middle finger rests on the upper surface, and a second axis perpendicular to the first, both axes being parallel to the lower surface; an opening in the lower surface; a light source mounted inside the housing, close to the opening and which illuminates the reflecting characteristics on the work surface; an optical motion detection circuit mounted within the interior of the housing and close to the opening, the motion detection circuit produces motion indication signals indicative of movement in the directions along the first and second axes and in relation to the illuminated reflective characteristics visible through the aperture; and a detector, coupled to the motion detection circuit, which detects when the movement of the pointing device within a time interval exceeds a selected limit, and which in response inhibits the production of the motion indication signals.

12. A device as in claim 11, wherein the optical motion detection circuit comprises a plurality of light detectors each having an output, a memory containing a referensia table of output values of the digitized photodetector and a frame of comparison of the output values of the digitized photodetector obtained subsequent to the reference frame, and wherein a new reference frame and the subsequent comparison table are obtained subsequent to when the detector detects only the movement of the pointing device exceeding the selected limit and before a resumption of production of motion indication signals. SUMMARY OF THE INVENTION An optical mouse reflects as a series of pixels the spatial characteristics generally of any microtextured or microdetailed work surface below the mouse. The responses of the photodetector are digitized and stored as a picture in memory. The movement produces successive frames of translated patterns of pixel information, which are compared by autocorrelation to check the direction and the amount of movement. A retention feature suspends the production of motion signals to the computer, allowing the mouse to be physically placed back on the work surface without altering the position on the pointer screen. This may be necessary if the operator operates outside the room to physically move to move the mouse further, but the screen pointer needs to go further. The retention feature can be implemented with a current button, a separate proximity detector or by detecting the presence of a characteristic condition in the digitized data, such as loss of correlation or overspeed of a selected limit. A convenient place for a current hold button is along the sides near the mouse button, where the opposite thumb and ring finger hold the mouse. The clamping force used to lift the mouse engages with the retention function. Retention can incorporate a short delay either by releasing the retention button, detecting the proper proximity or returning reasonable digitized values. During the delay, any lighting control or AGC server stabilizes the cycle. A new reference frame is taken before the resumption of motion detection.