Abstract:
A graphic aid device is disclosed which may be used with computers having a mouse-type computer cursor controller. The device provides a specific geometric orientation to the mouse, thereby enabling a tracing member attached onto or near the mouse to be used to manually trace complex figures while simultaneously and accurately transferring the complex figures to the computer memory. The device of the present invention utilizes a drawing machine arm to maintain a specific geometrical relationship of the mouse with respect to the surface over which the mouse is moved to trace the complex figure.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to a device for use with a computer for manual tracing of complex graphic curves and profiles from a drawing or the like which are simultaneously transferred into computer memory and, more particularly, to a device for use with a standard computer display controller to enable highly accurate translation of such complex curves and profiles from a drawing or photograph into computer memory. 
     2. Description of the Prior Art 
     With the proliferation of relatively inexpensive personal computers has come a strong demand for accessories for these computers enabling them to be used for an increasing number of tasks. Whether the application is for computer-aided design, complex mathematical analysis, or more mundane applications such as copying a drawing or a picture for display on a computer monitor, a popular activity with such personal computers is the transfer of a complex curve or profile from a drawing or photograph directly into computer memory by means of manually tracing the curve or profile from the drawing or photograph. 
     There are basically three types of devices which are capable of manually translating curves and profiles from a sheet of paper to the computer memory for filing, display, or printout, and these systems are the dedicated resolving system, the tablet type drawing system, and a computer cursor controller known as a &#34;mouse&#34;. 
     The first of these types of systems, the dedicated resolving system, has been around for some time, and is illustrated by U.S. Pat. No. 2,889,627, to Culpepper et al, and more recently by U.S. Pat. No. 4,331,954, to Bauman et al. The dedicated resolving system typically includes a complex electromechanical linkage system mounted on a tracing board and requires a complex sysem interface between the resolving system and the computer. Such systems are simply not practical for the use contemplated herein due to their high purchase price, which is easily several times the cost of the entire personal computer system. 
     The second type of system is the tablet type system, which is illustrated by U.S. Pat. No. 4,318,096, to Thornburg et al, as well as by U.S. Pat. No. 2,586,160, to Handel. The tablet type system may include either a small, portable tablet having an electrically sensitive surface or a larger, dedicated electrical table surface in which a curve or shape is inputted by use of a dedicated electrical pen. Various adaptations of this system exist, including those in which the user&#39;s finger may be used instead of a pen, as well as those systems utilizing light pen or torch screens. 
     The main drawbacks of such systems is that they are generally not very accurate unless they are also quite expensive. In addition, the use of such systems to trace curves or profiles from a drawing or photograph rather than directly on the tablet would either be substantially difficult or completely impossible, depending on the system. It is therefore evident that the tablet type system is not a practical solution to the unique requirements of the present design problem. 
     A third type of system experiencing rapidly increasing popularity utilizes a computer cursor controller device known as a &#34;mouse&#34;. A mouse is a pointing device generally for use with a visual display system or printout, and a transducer contained in the mouse converts translational motion of the mouse housing into a position signal which controls the movement of a cursor visually displayed on the computer monitor. By moving the mouse over a flat surface in the desired direction, the cursor will precisely follow the translation of the mouse. 
     The mouse typically contains a switch which is utilized to initiate a particular desired function. One of the functions personal computers are capable of performing with the mouse is generally known as the &#34;paint&#34; function. This function allows the computer operator to sketch images on the monitor by simply moving the mouse over the flat surface in the desired direction or directions, thereby making the mouse in effect a sort of pencil with which a drawing may be made to appear on the monitor. One such system also provides the capability of &#34;drawing&#34; straight lines and predefined curves and shapes on the monitor screen, according to shapes which are stored in the computer. However, this system is not able to reproduce complex curves and shapes with the accuracy that is desired. 
     It will be appreciated that the translation of complex curves and shapes from paper images to computer images is numerically very difficult to accomplish with any degree of accuracy, and the mouse has therefore become a popular device for performing such a function. The mouse typically contains a rotating ball and two optical sensors translating movements of the mouse to electrical signals to drive the cursor in the direction the mouse is moved. Another type of mouse utilizes only optical sensing of a grid-marked surface, but this type of mouse (which is shown in U.S. Pat. No. 4,364,034, to Kirsch) requires a grid-marked surface, which requirement may not be practical when copying figures on drawings or photographs. 
     Although the mouse goes a long way toward satisfying the need for a device enabling the translation of a complex image from a drawing to a computer, the mouse unfortunately has an inherent deficiency which makes highly accurate tracings of complex curves and profiles virtually impossible. This is inherent in the conventional use of the mouse, because the part of the mouse which acts as the actual pointer is the ball, which is centrally located underneath the mouse. It may immediately be appreciated that since the actual pointer of the mouse is underneath and in the center of the mouse, it is very difficult to trace with any degree of accuracy a curve or shape by moving the ball directly over the counter of the curve or shape. 
     A point on the side edge of the mouse can be used as the pointer, but since this location is offset from the ball of the mouse, which is the actual pointer, tracing done using this edge point will not be accurate unless the mouse is maintained in a fixed directional orientation while it is moved along the contours of the curve or drawing. What this means is that if the racing is commenced with the mouse pointed directly toward the top of the paper, the mouse must remain pointing directly toward the top of the paper while the tracing is manually performed. Failure to so orient the mouse will result in substantial error in the traced copy stored in the computer memory. 
     It may therefore be appreciated that there exists a substantial need for a device for use with the mouse which will automatically maintain the mouse in the desired orientation while the tracing process is carried out. The device must not get in the way of the tracing operation, and it must be adaptable to fit a presently existing mouse to avoid obsoleting all such devices sold prior to the existence of the present invention. This design, which will enable highly accurate tracings to be made with any mouse-computer combination, should also be inexpensive in order to afford the broadest possible market to personal computer owners. 
     SUMMARY OF THE INVENTION 
     The present invention is a tracing aid device for use with a standard mouse, which device provides a fixed orientation for the mouse while a tracing operation is performed. The invention utilizes a captive mechanisms substantially identical to the arm of a classic drawing or drafting machine used to maintain selected angles on a straight edge used to make drawings on a drafting table. The device is clamped onto the edge of a table, and a mouse is inserted into a receiving end of the arm located opposite the end clamped to the table in place of straight edges. Tracing means such as a pointer may be attached either to the mouse or to the receiving end of the drawing arm, the position of the pointer being an arbitrary choice designed primarily for the convenience of the user. 
     It may therefore be appreciated that, with such an arrangement, the mouse will be maintained in a fixed orientation while it is moved over the surface of the table, thereby causing the contour followed by the pointer to be exactly copied into the memory of the computer. In spite of the extraordinary accuracy of this device and the fact that it may be used with virtually any mouse and any personal computer interfacing with a mouse, it may be produced relatively simply and with a fairly low cost, thereby making it an inexpensive component which may be cheaply purchased by the large number of personal computer users. The device enables the mouse to be used to copy drawings, complex shapes, and photographs, and will find use in a large number of applications both in the home and in business operations. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A better understanding of the present invention may be had from a consideration of the following detailed description, taken in conjunction with the accompanying drawings in which: 
     FIG. 1 is a plan view of a standard computer mouse, showing the ball which is the actual pointer of the mouse in phantom lines, with the contact point of the ball connected by a phantom line to a pointer for use with the present invention, which has been added to the mouse; 
     FIG. 2 shows the mouse of FIG. 1 in side view; 
     FIG. 3 illustrates the present invention clamped to a table at one end, and containing the mouse of FIGS. 1 and 2 in the other end; 
     FIG. 4 depicts an alternative embodiment of the present invention using a different type of drawing machine arm; 
     FIG. 5 shows a variation of the arrangement of FIG. 3; 
     FIG. 6 illustrates a variation of the device of FIG. 5; and 
     FIGS. 7A and 7B show further modifications in the device of the invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A typical mouse 10 is shown in FIGS. 1 and 2. As mentioned above, translational motion of the mouse 10 over a flat surface causes movement of a ball 12, which movement is converted by a transducer inside the mouse 10 into a position signal supplied to a computer through a cord 15, which position signal typically controls movement of a cursor on a video monitor driven by the computer. The mouse 10 contains a button 16, which is used to select particular desired functions generally listed on the video monitor. 
     It will therefore be appreciated that the actual pointer of the mouse 10 is the point of contact between the surface of the ball 12 and the flat surface on which the mouse device 10 is being moved. The mouse 10 shown in FIGS. 1 and 2 is entirely a standard device, with the exception of the addition of a pointer 20, which may be adhesively attached to the side edge of the mouse 10. The actual location of the pointer 20 at the location illustrated in FIGS. 1 and 2 is arbitrary, as will be further explained below. 
     The geometric relationship between the location of the actual pointer of the mouse 10 and the pointer 20 is defined by a line 30 therebetween. Elementary geometric principles hold that maintaining orientation of the line 30 in a fixed direction while moving the mouse 10 over a flat surface will cause movement of the actual pointer of the mouse 10 (defined by the intersection between the ball 12 and the flat surface) and movement of the pointer 20 to exactly correspond. Therefore, if the line 30 is kept in the specific geometric orientation while the mouse 10 is moved over the flat surface, movement of the pointer 20 along a curve or profile will result in that curve or profile being reproduced exactly in the memory of the computer and on the video display. 
     Another way of summarizing this relationship is by considering the flat surface to be defined by two orthogonal lines, for example X and Y axes of FIG. 3. The line 30 will be kept in a unique angular relationship with the two orthogonal lines, thereby causing the tracing of a complex curve or profile to result in the complex curve or profile being exactly reproduced in the computer memory and on the video monitor. 
     Referring now to FIG. 3, the mouse 10 shown in FIGS. 1 and 2 is shown mounted in a specific geometric orientation above a flat surface provided by a table or drawing board 40. It will be appreciated that the specific geometric orientation shown in FIG. 3 has the line 30 (FIG. 1) of the mouse 10 moving in a parallel relationship with the Y-axis of the table 40, although other geometric relationships are possible. The only requirement is that the specific geometric relationship of the line 30 (FIG. 1) of the mouse 10 be maintained parallel with respect to a line contained in the surface of the table 40 (and therefore maintain unique angular relationships with the two orthogonal lines defined by the X and Y axes.) 
     In one preferred embodiment of the present invention, a drawing arm 50 of the mechanical linkage type is used to maintain this geometric relationship, the drawing arm 50 being of standard design which is well known in the art. The drawing arm 50 is supported from the table 40 at one end by a mounting bracket 52, which is securely fastened to the edge of the table 40. 
     At the other end of the drawing arm 50 is a receiving bracket 54 adapted to receive the mouse 10 in a manner allowing the ball 12 of the mouse 10 (FIGS. 1 and 2) to rest on the flat surface of the table 40. Due to the operation of the drawing arm 50, the receiving bracket 54 and the mouse 10 may be freely moved over the surface of the table 40 in the X direction, the Y direction, or any combination thereof. Throughout the locus of such movement of the mouse 10 over the surface of the table 40, the specific geometric orientation of the mouse 10 will be maintained constant by the drawing arm 50. 
     It should be noted at this point that the drawing arm 50 may be fixedly oriented to the table 40 by the mounting bracket 52 being mounted at any location about the table 40, preferably at a location making movement of the mouse 10 convenient for the user of the device. As mentioned above, the location of the pointer 20 on the outside edge of the mouse 10 as shown in FIGS. 1-3 is entirely arbitrary, although it is felt that the location at the side of the mouse 10 facing the user of the device will be the most convenient location for the pointer 20. The pointer 20, however, could be mounted at other locations on the mouse 10, or also at any location on the edge of the receiving bracket 52, or indeed on the receiving bracket 52 itself, should it be made of a transparent material. It will be appreciated that the only necessary requirement for the location of the pointer 20 is that it be referenced in a fixed position with respect to the actual pointer of the mouse 10, namely the contact point of the ball 12 with the flat surface of the table 40. Therefore, a line 30 drawn from this actual pointer to the pointer 20 will always be maintained in a parallel relationship to a line running through the surface of the table 40, and at unique angular positions relative to the X and Y axes. 
     An alternative embodiment of the present invention is shown in FIG. 4, using a different type of drawing or drafting machine arm 60 consisting of vertical and horizontal bars. A horizontal bar 62 is mounted on the top edge of the table 40, and a vertical bar 64 slides back and forth on the horizontal bar 62. The receiving bracket 66 slides up and down on the vertical bar 64, and therefore is free to move over the flat surface of the table 40, while being restrained from angular movement with respect to the X and Y axes. This embodiment operates in a similar manner to the embodiment shown in FIG. 3, but is generally more expensive to manufacture. 
     FIG. 5 shows a portion of the arrangement of FIG. 3 with the receiving bracket 54&#39; modified to allow some variation of the orientation of the mouse 10 for the convenience of the user in following the line 14. Also, in this arrangement, the pointer 20&#39; is affixed to the receiving bracket 54&#39; instead of directly to the mouse 10. 
     As shown in FIG. 5, the receiving bracket 54&#39; comprises a base plate 70 and an adjustable plate 72. The base plate 70 is fixedly mounted to the drawing arm 50 in the manner of mounting the receiving bracket 54 in FIG. 3. The mouse 10 is oriented in the position shown, nested within a receiving opening 74 in the adjustable plate 72. The adjustable plate 72 is pivotably mounted to the base plate 70 by a pin 76. A slot 78 permits rotation of the adjustable plate 72, within limits, about the pivot pin 76. When adjusted to the desired position relative to the base plate 70, the plate 72 is locked in position by tightening a knurled nut 80 which is mounted on a threaded stud 82 extending from the base plate 70. This arrangement allows the user to adjust the plate 72 relative to the base plate 70 in order to minimize the degree to which a curve or line being followed is covered up by the receiving bracket 54&#39;. This adjustment would be set in the beginning of any curve tracing operation and would not be changed during the entry of the traced curve configuration into the computer. After setting the position of the adjustable plate 72 relative to the base plate 70, the reference point for the curve could be entered into the computer, if desired, merely by moving the pointer 20&#39; to that point and pressing the switch button on the mouse 10. 
     FIG. 6 shows a variation of the arrangement of FIG. 5 in which a tracing element 20&#34; having a lens 90 is mounted on the receiving bracket 54&#39; instead of the pointer 20&#39;. As shown in FIG. 6, the lens 90 is mounted in a lens holder 92 and has a pair of cross hairs 94 for locating the line 14 with greater precision. 
     Devices in accordance with the present invention may also be provided with a small light, as shown in FIGS. 7A and 7B, to illuminate the section of the line 14 in the immediate vicinity of the tracing element. FIG. 7A shows the bracket 54&#34; in partial sectional view as having a cavity 100 in the housing adjacent the pointer 20&#39;. The cavity 100 is shown containing a bulb 102, a pair of dry cells 104, and a switch 106. An aperture 108, preferably covered with a thin piece of transparent plastic, permits light from the bulb 102 to illuminate the optical field in the immediate vicinity of the pointer 20&#39;. 
     A corresponding arrangement for the tracing lens arrangement 20&#34; of FIG. 6 is depicted in FIG. 7B, wherein a bulb 102&#39;, cells 104&#39; and switch 106&#39; are mounted within a cavity 100&#39;, from which light may emanate through the aperture 108&#39; to illuminate the area immediately underneath the lens 90 in which the line being traced is positioned. 
     The present invention may be adapted for installation on virtually any table, and for use with any commercially available mouse. The present invention affords a highly accurate transfer of a complex curve, profile or other complex figure from a drawing or photograph to the memory of a computer, or to a video display or a dot matrix or other type of printout. The simple design of the present invention utilizing the principles of the classic drawing machine arm make the present invention relatively inexpensive to manufacture, and therefore a highly affordable accessory for use with personal computers having a mouse. This highly accurate translation device will find substantial use in commercial as well as domestic environments, and represents a significant improvement over previously known translation devices. 
     Although there have been described above specific arrangements of a tracing aid for computer graphics in accordance with the invention for the purpose of illustrating the manner in which the invention may be used to advantage, it will be appreciated that the invention is not limited thereto. Accordingly, any and all modifications, variations or equivalent arrangements which may occur to those skilled in the art should be considered to be within the scope of the invention as defined in the annexed claims.