analog joy stick pointing device

Field of the Invention

This invention relates in general to analog joystick pointing devices and in particular to an improved pointing device.

Description of Related Art

US-A-5 317 301 and US-A-5 087 904 generally relate to joysticks.

Analog joysticks are known in the art such as shown by US-A-4 857 881, US-A-4 864 272 and US-A-4 685 678. They generate analog signals representative of coordinate position, where a pair of members is movable in orthogonal directions by a handle.

A joystick pointing device having the features of the preamble part of claim 1 is disclosed in EP-A-0 640 937. A control element includes strip contacts that are arrayed in a ring along a circle for making contact with grouping contacts on the conical bottom surface.

Another joystick as described in EP-A-0 089 295 includes a conductive spring in connection with a lever which is pivotally mounted within the hole of a support.

EP-A-0 286 388 discloses a pivoting mechanism in a joystick structure, wherein the center of a cylindrical portion has a rib which provides a support for a transversely extending axle part mounted in a recess in a side wall of the housing in order to enable rotation of the axle part. The axle part is a prolongation of a lever which, if manually pressed, deforms a member having an electrically conductive surface portion which is arranged to engage a continuos area or track or resistive material such that as a changing manual pressure is applied to the lever a changing amount of the track is electrically bridged or short circuit by said conductive surface portions.

US-A-4 433 217 proposes to replace a joystick by a hand-held controller which comprises an electrical switch means for producing electrical signals indicating the direction in which the cursor on a display should move in response to motion of the top portion of the hand controller relative to a spherical surface acting on a conductive pattern.

The problem to be solved by the invention is to provide an analog joystick pointing device having a quicker response as the devices or the prior art.

This object is solved by an analog joystick pointing device as defined in claim 1. Preferred embodiments are subject-matter of subclaims 2 to 15.

Other objects, features and advantages of the invention will be readily apparent from the following description of certain preferred embodiments thereof taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

• FIG. 1 is a perspective view illustrating the invention connected to a computer;
• FIG. 2 is a sectional view illustrating the invention; and
• FIG. 3 is a sectional view illustrating the invention.
• Figs. 4 to 13 give background information and show possibilities to modify the invention without being embodiments thereof.
• FIG. 4 is a sectional view illustrating a modification ;
• FIG. 5 illustrates a modification;
• FIG. 6 is a plan view of the circuit board and the resistors and conductive paths thereon;
• FIG. 7 illustrates a modified form of the circuit board;
• FIG. 8 illustrates a modified form of the circuit board;
• FIG. 9 illustrates a modified form of the circuit board;
• FIG. 10 illustrates a modified form of the circuit board;
• FIG. 11 is a plan view of the center contacts;
• FIG. 12 illustrates a modification of the center contacts; and
• FIG. 13 is a detailed view of the electrical paths on the printed circuit board;
• FIG. 14 illustrates a modified form;
• FIG. 15 shows the resistive coating of the device of FIG. 14;
• FIG. 16 illustrates the point of triangulation of the device of FIG. 14; and
• FIG. 17 illustrates the theory of triangulation for the device of FIG. 14.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The invention comprises an analog joy stick pointing device which uses a board such as a printed circuit board, glass, paper, ceramic or plastics which have conductive lines and resistive coatings formed on it or embedded or otherwise provided on the surface. The board has a hole that can be plated on its inner surface and separated with laser, drilling or routing. A spring fits through the hole at a 90° angle and normally the spring does not make electrical contact with the board when external forces are absent. The spring or a sheath around the spring is electrically conductive and the spring or sheath is biased with a voltage. When the spring or sheath is deflected by a user, it bends and makes electrical contact with the conductor within the hole. The board has electrical contacts (digital) that are closed when an external force is applied. Signals so developed are supplied to a microcontroller either or both to wake up the micro-controller and tell it the direction plus speed. Because a digital contact is used, there is not a long analog to digital conversion time. The equation is (1.1) X (resistance maximum) X (Capacitance) = maximum conversion time, which is needed by analog only joy sticks or pointing devices. In the absence of the conversion delay time by using only digital input leads allows rapid movement, which makes the present joy stick very quick to respond to the user's initial movements of the stick. The speed is determined and only limited by the speed of the micro-controller wakeup routine plus the time to send the message to the receiver. Once there is movement caused by the closure, the micro-controller then looks at the analog portion of the signal to determine how much faster to move. If the user releases the force and allows the stick to move back to the neutral position, the firmware can interpret this as a MACRO function. For example, this function can mean TAB, move to next icon, move by page or it can be the same step as normal without using macros. Upon further prolonged force/deflection, a contact is made or increased via the force diverter that causes contact on the analog/digital signal speed/direction interpreter. The micro-controller then converts this data with the earlier contact and determines various speeds and directions resulting in multiple speeds and multiple directions which are possible. The direction possibilities are at least two to infinite and speeds may be at least two to infinite. The larger the displacement of the diverter, the further out the contact is made with the analog/digital circuitry, thereby causing a variable signal which is due to the angular displacement of the spring/stick. Upon release of all the external forces by the user by letting go of the spring (stick), it moves back to its normally biased position which does not make contact with the initial digital contacts and the force diverter that is attached to the spring also moves back to the initial state. In its initial state, the force diverter can be making contact on the digital analog output section or can also not be making contact. If the force diverter is making contact in the neutral state, the micro-controller ignores this information by zeroing out this condition. The force diverter can be electrically active conductive or can be a pressure transfer point causing a variable closure on a membrane switch. The corresponding increase in force on the force diverter either increases the surface area of contact for change in resistance or it changes the absolute point of contact on the analog/digital contact thereby changing the point of the voltage potential. This changes the analog voltage. Software in the micro-controller interprets such data and sends an output to a relevant receiver which can be connected by a wire or otherwise connected.

Another novel feature of the pointing device is the "fan out" method that the circuit path traces from the resistor, thus, allowing the interleaving of the various traces for different speeds at different angles of displacement.

FIG. 1 is a perspective view illustrating the novel joy stick/pressure pad of the invention mounted in a container 10 which has a top surface 11. Cables 12 and 13 extend from the container 10 and join in a cable 14 that is connected to a micro-controller 16 that is associated with a monitor 17 and a keyboard 18.

FIG. 2 is a sectional view of the joy stick of the invention wherein the container 10 has a bottom 22 and side walls 21 and a top wall 11 formed with an opening 30. A spring 27 is mounted in a boss 24 formed in the bottom wall 22 and extends upwardly through an opening in a printed circuit board 23 mounted in container 10 and which has electrical conductive paths 41 and 39 formed on the inner surface of the opening and the printed circuit board. A force diverter 36 is mounted on the spring 27 and at least the outer surface is electrically conductive. It may be made, for example, of low durometer rubber and has a lower conductive surface which can engage printed circuit paths 39 on the printed circuit board 23 when the spring 27 is deflected from its center position. The spring 27 extends through the opening 30 in the top surface 11 and a stick 31 has an opening 32 in which the spring is received. The stick has a downwardly extending generally conical portion 33 which joins an outer flat portion 34 that engages the force diverter 36. When the stick 31 is moved, it causes the spring 27 to be deflected so it engages the surface of the conductors 41 formed in the opening in the printed circuit board 23 and also causes the force diverter 36 to engage the printed circuit paths 39 on the printed circuit 23. The container 10 may be made of non-conductive material and an electrical voltage is applied to spring 27 by a conductor 6 so as to provide an energizing voltage.

FIG. 3 illustrates the joy stick 31 in a deflected from neutral position wherein the outer conductive surface 37 of the force diverter 36 engages the printed circuit conductors 39 and a sheath 28 which is electrically connected to the spring 27 makes electrical contact with one of the conductors 41 in the opening in the printed circuit board. The center of the force diverter 36 may be hollow or filled with a suitable filler such as plastic 38.

As mentioned above, the devices shown in Fig. 4 to 13 are no embodiments of the invention, but included as background information only.

FIG. 4 illustrates a slightly modified form wherein the spring 47 has a first end 48 that is mounted by a sleeve 49 in a bottom plate 46 of the container 10, and the upper end of the spring is received in the hollow insides 92 of a stick 51 which attaches to a bottom plate 53 which engages the force diverter 54. The spring fits in the opening 92 in the stick 51. By moving the stick 51, the force diverter will engage the conductive paths 39 on the printed circuit board 23 and the spring 47 will engage the conductive paths 41 on the inside of the opening in the printed circuit board 23.

FIG. 5 illustrates a further modification wherein the force diverter 61 may be made of a flexible substance such as low durameter rubber and has a portion which extends through an opening in the printed circuit board and terminates in an enlarged portion 62. A stick 63 extends through the opening 30 in the top cover 11 and has a lower flat portion 64 which engages the force diverter 61 to move it to engage the circuit paths 39 on the printed circuit board 23.

FIG. 6 illustrates in plan view the circuit board 23 and includes a first plurality of parallel conductors 121a through 121f mounted on a first segment portion of the board. A resistive path 126 extends at right angles to the conductors 121 and makes electrical contact therewith. A second plurality of electrical conductors are formed in another segment of the printed circuit board 123a through 123f and are designated 122a through 122f and a resistive path 127 extends at right angles to the conductors 122a through f and makes electrical contact therewith. A third plurality of conductors 123a through 123f are also mounted on the board in a different segment and are electrically connected to a resistive path 128 which extends at right angles thereto. A fourth plurality of conductors 124a through 124f are mounted on another segment of the board 23 and are connected to a resistive path 129 which extends at right angles thereto. The spring 47 when deflected engages the conductors 41 on the inside of the opening and the force diverter 54 engages the printed circuit board.

FIG. 7 illustrates another arrangement of the printed circuit board 23 wherein a first plurality of printed circuit paths in the form of segments of a circle 131a-131i are formed in a first segment and are traversed by resistive path 136. A second plurality of curved segments 132a-132i are formed on the printed circuit board and are traversed by a resistive path 137. A third plurality of curve segments conducted paths 133a-133i are formed on the board and are traversed by resistive path 138. A fourth plurality of curve segments 134a-134i are mounted on another segment of the printed circuit board 23 and are traversed by resistive path 139. The opening through the printed circuit board is formed with four separate conductive paths 101, 102, 103 and 104 which are separated from each other as shown.

FIG. 8 is a modification of the circuit board of FIG. 7 wherein a radially extending printed circuit path 146 is mounted in the space between a first plurality of curved segments 141a-141e and a second plurality of curved segments 142a-142e. Circuit paths 147, 148 and 149 extend from the radial circuit path 146 between the curved segments 141 and 142 as shown.

Other radial circuit paths 151, 156 and 161 extend through the gaps between the curved conductive paths 142a-3 and 144a-3 as shown. Radial circuit path 151 has transverse extending conductive paths 152, 153 and 154 as shown. Radial circuit path 156 has transverse extending circuit paths 157, 158 and 159 as shown. Radial circuit path 161 has extending transverse circuit paths 162, 163 and 164 as shown. The spring 47 is engageable with the conductive segments 101, 102, 103 and 104 when deflected.

FIG. 9 shows another modification wherein circuit paths 216, 217, 218 and 219 are interwoven between the curved circuit paths such as 213a-213f and 214a-214f and extend at angles which are not perpendicular to radials so as to increase the quantity of speeds that are available in diagonals. It is to be realized, of course, that the interwoven fingers such as 216-219 would also be formed between the segments 212a-212f and 213a-213f as well as between the segments 211a-211f and 212a-212f and also between the segments 211a-211f and 214a-214f.

FIG. 10 illustrates a printed circuit board 23 which is formed with additional separated curve segments so as to increase the angular resolution of the device. First parallel curve segments 192a-192i are traversed by resistive path 181. Second segments 193a-193i are traversed by resistive path 182. A third plurality of segments 194a-194i are traversed by resistive path 183. A fourth plurality of segments 196a-196i are traversed by resistive path 184. A fifth plurality of radial segments 197a-197i are traversed by resistive path 186. A sixth plurality of radial segments 198a-198i are traversed by a resistive path 187. A seventh plurality of conductive paths 199a-199i are traversed by a resistive path 189 and a eighth plurality of conductive paths 201a-201i are traversed by resistive path 191 as shown. This increases the angular resolution of the device by a factor of two over the board shown in FIGS. 6 and 7 for example.

FIG. 13 illustrates in detail the manner of connecting the various electrical conductive paths to an external circuit. The conductive portions 101, 102 and 103 and 104 formed in the opening of the printed circuit board 23 are connected to terminals as shown which are then connected by conductive paths to terminals such as 309. Curved segments 131 are each connected to different terminals and are connected by leads such as 302 and 303 to different terminals 304. Other segments are each connected to different terminals such as 306 which are connected to different remote terminals 304 by conductive path 5.

Thus, the present invention provides a novel joy stick which allows many different orientations to be recognized and sent to a control device, as well as allows the amount of deflection of the joy stick or pressure pad to be detected, so as to provide a control signal.

FIGS. 14, 15 and 16 illustrate a modification which includes a substrate 401 upon which is formed an annular shaped resistive material layer 402.

Conductive pads 407, 408, 409 and 410 contact the outer edges of the layer 402 as shown. Electrical leads 412, 413, 414 and 415 are respectively connected to conductive pads 407, 408, 409 and 410 as shown.

Digital input conductive traces 403, 404, 405, and 406 are formed on substrate 401 within the annular shaped resistive material layer 402.

When deflected, the force diverter, not shown in FIGS. 14, 15 and 16 engages the resistive layer 401 at point (P) 417, for example, as shown in FIGS. 16 and 17.

The resistive value at point P can be found as shown in FIG. 17 in the following manner:

To find the co-ordinate of point P, we first find the shortest distance from a, b, c, d, using the analog conversion. Once this is completed, we triangulate between the three closest points with respect to their polar position. One example is as shown whereby point P is closest to point b in the upper left quadrant.

Our knowns are:

$${\text{Y}}_{\text{T}}\text{= Constant}$$$${\text{X}}_{\text{T}}\text{= Constant}$$$${\text{y}}_{\text{1}}{\text{+ y}}_{\text{2}}{\text{= Y}}_{\text{T}}$$$${\text{x}}_{\text{1}}{\text{+ x}}_{\text{2}}{\text{= X}}_{\text{T}}$$$$\sqrt{{\text{(x}}_{\text{1}}{\text{)}}^{\text{2}}{\text{+ (y}}_{\text{1}}{\text{- 0.5Y}}_{\text{T}}{\text{)}}^{\text{2}}}\text{= a'}$$$$\sqrt{{\text{(y}}_{\text{2}}{\text{)}}^{\text{2}}{\text{+ (0.5X}}_{\text{T}}{\text{-x}}_{\text{1}}{\text{)}}^{\text{2}}}\text{= b'}$$$$\sqrt{{\text{(x}}_{\text{2}}{\text{)}}^{\text{2}}{\text{+(y}}_{\text{2}}{\text{)}}^{\text{2}}}\text{= c'}$$ Thus, the voltage at contact point P can be determined relative to the contacts 407, 408,409 and 410 and from these values, the position of point P can be determined.

Although the invention has been described with respect to preferred embodiments, it is not to be so limited as changes and modifications can be made which are within the full intended scope of the invention as defined by the appended claims.