GB2505323A

GB2505323A - Controlling a display screen by varying the resistance in a stylus

Info

Publication number: GB2505323A
Application number: GB201315016A
Authority: GB
Inventors: Stephen John Carpenter
Original assignee: CONCEPTIONEERING Ltd
Current assignee: CONCEPTIONEERING Ltd
Priority date: 2012-08-23
Filing date: 2013-08-21
Publication date: 2014-02-26
Also published as: EP2888647A1; GB201215048D0; WO2014029955A1; GB201315016D0

Abstract

Apparatus comprises; a processor 11 with an output terminal 22B and an input terminal 22A for an electrical signal; a controller 13 for receiving a signal from the output terminal and returning the signal to the input terminal, the controller comprising pressure-sensitive means responsive to change in pressure thereon to vary the signal as a function of the change; and a screen 12 for displaying an image, the image influenced by the processor based on the varied signal. The signal might be an audio signal that is transmitted from and received by a combination headphone-loudspeaker port at the processor. The controller might be a stylus having a nib 15. The nib is displaceable by being pushed which moves a member or wiper 18 of a potentiometer 16, and this alters the resistance or impedance of the circuit which in turn modifies the signal. The screen might be a touch-sensitive screen.

Description

APPARATUS WITH CONTROL BY AUDIO SIGNAL

The present invention relates to apparatus with control by audio signal, especially apparatus comprising a processor, an image display screen and a controller.

It is known to control a processor by means of moving a finger or stylus across a suitable screen. Such an arrangement is common with tablet computers and smart phones. Styli are usually of one of two forms, a basic stylus which simply points to a position or draws a line on the screen and which does not have a power supply (battery) and a more sophisticated arrangement in which the stylus includes a battery power supply. The more sophisticated styli can carry out more functions.

Also known are various forms of styli capable of producing variations in markings created on image display screens by the styli. In one example of such a prior art stylus, as disclosed in US 2005/0122319 Al, the stylus has a pressure-responsive pen tip with a downstream arrangement of pressure detecting circuit, microcontroller, battery and infrared signal output circuit. The output circuit co-operates with a receiver comprising an infrared signal receiving circuit and another microcontroller, which in turn transmits control data to a host machine, i.e. computer. Such a system is of substantial complexity and cost with multiple functional units containing components capable of failure. The stylus itself is not only powered, but based on active signal generation in order to relay control data to the host via a special intermediary.

It is therefore the object of the present invention to provide apparatus in which communication between a controller, for example a stylus, and a processor can be carried out directly and by simple and cost-effective means, especially through utilisation of a signal input and output facility commonly present in processors and often unused or under-used in practice.

Other objects and advantages of the invention will be apparent from the following

description.

According to the present invention there is provided apparatus comprising a processor with an output terminal and an input terminal for an audio signal, a controller for receiving an audio signal from the output terminal and returning the audio signal to the input terminal so as to be connected with the processor in an audio feedback loop, the controller comprising pressure-sensitive means responsive to change in pressure thereon to vary the audio signal as a function of the change, and a screen for displaying an image, the processor comprising control means responsive to the varied audio signal to influence the displayed image in dependence on the variation.

Such apparatus has the advantage of influencing an electronically generated image by the comparatively benign and cost-effective measure of an audio feedback loop utilising an audio output and audio input such as are commonly present in processors of a wide range of categories and purposes. The audio feedback loop is, in effect, electrically passive and the controller consequently can be non-powered, which apart from advantages with respect to safety permits use of simple and inexpensive components for signal parameter change.

In a preferred general construction of the apparatus the processor can be, for example, a computer with a suitable screen, a tablet computer, a games console or a smart phone, which has a first terminal, for example a headphone socket, for outputting a signal capable of providing an audio output on a speaker, headphones or other audio device and a second terminal, for example a microphone socket, capable of receiving a signal from a microphone or other audio device. Such an audio signal can be an electrical signal, which when applied to a speaker will provide an audio output, or in part a radio-frequency signal, for example a signal of the kind used in Bluetooth communication. The processor includes first means for controlling the processor to provide a signal on the first terminal and the controller comprises second means for receiving an audio signal from the second terminal, third means to vary the signal received at the second means, for example by changing its amplitude or frequency, which third means may be controlled manually to vary the signal and is preferably without a power source, and fourth means to pass the varied signal back to the second terminal of the processor. Conveniently, the second and fourth means may comprise a combined headphone-speaker/microphone connector. The control means constitutes fifth means to control the processor to carry out an operation depending on the varied signal received at the second terminal. It will thus be understood that in such a preferred embodiment the normal ability of a processor to provide an audio signal at, for example, a microphone input socket, is harnessed to control a function of the processor, for example to vary the appearance of a line traced on the screen by the controller.

For preference, the screen is a touch-sensitive screen and the pressure-sensitive means comprises a nib for causing generation of an image of a mark on the screen by contact of the nib with the screen, the nib being displaceable in response to change in the contact pressure between the nib and screen to vary the received audio signal and the control means being responsive to the varied audio signal to change the size of the mark in dependence on the variation. The controller thus represents a simple and effective means of exercising control, based on an audio feedback loop, of an aspect of a displayed image, specifically the size of a mark produced by a tip of the nib. The controller includes a nib to touch the screen and to provide a suitable input, which may be a capacitive electrical value, to the screen to control the processor. The nib may include a conductive surface provided by, for example, constructing the nib from a conductive material or otherwise providing the nib with a conductive coating.

In the case of such a controller and screen construction the nib is preferably movable across the screen to cause generation of an image of a line thereon and the control means is responsive to the varied audio signal to change the width of the line. In effect, the controller can be passed across the screen to provide information to the processor, for example the controller may cause the processor to provide a line following a line traced by the nib on the screen. The varied audio signal when returned to the processor will cause the processor to provide a line on the screen of a thickness which changes depending on the pressure-related displacement of the nib. The controller can accordingly be used to draw a line with a thickness proportional to the nib contact pressure on the screen, which opens up possibilities of using the apparatus for drawing, writing and design activities without requiring powered operation of the controller or complex componentry within the controller.

In a preferred construction the controller comprises a body and the nib is slidably mounted in and protrudes from the body, in which case the nib is preferably resiliently biased in a direction of maximum protrusion from the body. The controller can have the form of a stylus, especially a capacitive-type stylus. In effect, the afore-mentioned second, third and fourth means are embodied in a controller shaped as a stylus of a type recognised by the screen.

For preference the variation produced by pressure-sensitive means is a variation of a voltage, which is a magnitude readily capable of variation by a wide range of simple and inexpensive devices. With advantage the controller comprises variable impedance means, such as a potentiometer, especially a linear slider potentiometer, for varying the audio signal and the pressure-sensitive means is displaceable to vary the impedance at the impedance means. The pressure-sensitive means, for example the afore-mentioned nib, can then be fixed to a wiper of the potentiometer so that there is a direct mechanical association with the pressure-sensitive means and the component actually producing the signal variation and any need for transmission or translation of the displacement of the pressure-sensitive means is eliminated. In effect, the afore-mentioned third means can comprise a potentiometer or variable resistor, including a quantum tunnelling composite, to vary, for example, the amplitude of an audio signal passed to the second terminal. In the case of a controller having the form of a stylus, when pressure is applied to the nib this causes the potentiometer or resistor to vary the output audio signal of the stylus. In a simple arrangement the nib may be spring-loaded with respect to the remainder of the stylus to produce or oppose (depending on direction) relative movement of two components of a potentiometer so as to vary the output signal. A variable impedance means such as a potentiometer represents a particularly simple, inexpensive and lightweight component which is readily available as a proprietary component usually with, due the minimal number of working parts and long-established development, proven reliability and long service life.

As an additional feature the controller can comprise sound reproduction means to reproduce sound provided by a further audio signal from the processor, which enhances the capability of the controller by allowing association of audible instructions, a narrative, etc., with an image currently displayed by the screen or with the manipulation of the controller. Thus, in a particularly preferred embodiment, the controller in the afore-mentioned of a stylus can include a speaker which is connected to receive an audio signal from the processor, preferably via an unused stereo headphone-speaker line. In use, this speaker may play music or the like or other sounds such as spoken information.

The variation of the audio signal is preferably a variation of at least one of amplitude and frequency, which can equate with change in the volume represented by the audio signal.

Prior to variation thereof the audio signal can be of constant amplitude, thus advantageously a simple signal representing a monotone of selected pitch and volume.

For preference the controller has a wired connection with the output and input terminals and the audio signal is an electrical signal along the entire length of the feedback loop.

This signifies that, for example, the afore-mentioned second and fourth means can be provided by wires and connectors for connecting the controller with the first and second terminals. A wired connection represents a particularly simple and inexpensive means of conducting the audio signal in the feedback loop, with only the relatively inconsequential penalties of a constrained association of the portable controller with the stationary processor and drag by the connecting lines. Altematively, however, the controller can have a wireless connection with the output and input terminals and the audio signal can be a radio signal in the sections of the feedback loop between the processor and the controller. In that case the required audio signal and sound can be transmitted over an audio RF link such as Bluetooth. However, the controller will then need powered componentry and will be an active, rather than the more desirable passive, device.

In one preferred format of the apparatus the screen is integrated in the processor, but the processor and the screen can equally well be separate units. Thus, the screen can be constructed integrally with the processor such as when it is a laptop, tablet, smart phone or games console or may be separate when the processor is a personal computer of suitable type.

For preference the control means comprises software in the processor, whether embedded or downloadable from a suitable data carrier. In effect, the afore-mentioned first means and fifth means comprise software to generate the output audio signal at the first terminal and to control the processor in accordance with the signal received at the second terminal, the software preferably being in the form of an app'. Appropriate control of the processor can therefore be achieved solely by way of software without any need for change to or addition of hardware of any kind.

The pressure-sensitive means can be manually displaceable by a user so that the controller is usable as a joystick. This form of use can be additional or alternative to the described use as a marking instrument.

A preferred embodiment of the present invention will now be more particularly described by way of example with reference to the accompanying drawings, in which: Fig. I is a block circuit diagram of apparatus, composed of a processor, screen and controller, embodying the invention; Fig. 2 is a schematic elevation of the controller in the embodiment of Fig. 1; Fig. 3 is a detail view, to enlarged scale, of part of the controller of Fig. 2, with a displaceable nib thereof in fully extended state; Fig. 4 is a view similar to Fig. 3, but with the nib in a partly retracted state; and Fig. 5 is graph showing, in diagrammatic form, the relationship between displacement of the nib and the size of a mark produced on the screen by the nib.

Referring now to the drawings, there is shown in Fig. 1, in block diagrammatic form, apparatus 10 comprising a processor 11, a touch-sensitive image display screen 12 and a controller 12, here in the form of a stylus. The processor 11 can be, for example, a computer, a tablet computer, a games console, a smart phone or other form of data processing equipment and the screen 12 can be integrated in or separate from the processor. The screen is preferably integrated in the processor, but is shown separately in Fig. Ito more clearly distinguish the principal components of the apparatus.

The stylus 13 comprises a generally tubular body 14 in which is slidably mounted an elongate pressure-sensitive member in the form of a generally cylindrical nib 15. The nib protrudes at one end from the body 14 and is axially displaceable against a resilient bias in response to pressure exerted on the end face of the protruding end, in particular as a consequence of pressurable contact of the end face with a pressure-sensitive surface of the screen 12. The nib 15 is made of or coated with electrically conductive material.

The nib 15 is associated with a linear slider potentiometer 16 comprising a resistive member 17 and a wiper 18, the latter being fixed to the nib remote from its protruding end.

Consequently, axial displacement of the nib directly causes movement of the wiper 18 along the resistive member 17 and thus change in an electrical value tapped from the potentiometer in accordance with the conventional purpose of a potentiometer.

Also present in the stylus 13 is a speaker 19 accommodated in a sound amplification chamber 20 of the stylus body 14.

The circuit in which the processor 11, screen 12 and stylus 13 inclusive of nib 15, potentiometer 16 and speaker 19 are electrically incorporated is shown in simplified form in Fig. 1. The processor 11 contains software, preferably in the form of an app' loadable by a user into the processor, to control the screen 12, in particular the image displayed by the screen, and is in control communication with the screen by way of a line 21. In practice, such a line will be realised by a data exchange link which, if the screen is integrated in the processor, may be provided by a suitable integrated circuit. The line 21 simply symbolises the link.

The connection between the processor 11 and the stylus 13, which in the illustrated embodiment is a wired connection, is provided by electrical lines 22A, 228, 220 and 220 coupled with an audio output terminal and an audio input terminal of the processor. The terminals are shown as separate terminals in Fig. 1, but in practice will generally be provided by a combined headphone-speaker/microphone socket.

The line 22A is connected with the wiper 18 of the potentiometer 16 via a conductive path of the nib 15, specifically the, conductive material of the nib or of its coating. The conductive path can, however, be realised by other means. The lines 22B and 22C are respectively connected with two end terminals of the resistive member 17 and the line 220 additionally with one of two drive terminals of the speaker 19. The line 22D is connected with the other one of the drive terminals. In an exemplifying arrangement, the line 22A can provide an audio input (microphone input signal) to the processor 11 and the lines 22B and 22D audio outputs (left and right stereo speaker-headphone output signals) from the processor. The line 220 can be a ground line. The respective association of the lines with the input, outputs and earth can be changed in accordance with usual electrical connection principles and the stylus can incorporate a switch (not shown) to produce such a change, in particular for compatibility with different audio system sockets.

The stylus 13, more specifically the nib 15, is thus connected with the processor 11 in an audio feedback loop represented by the lines 22A to 22C, nib 15 and potentiometer 16, whereby an electrical value of an audio signal in the loop can be varied by the potentiometer 16 as a function of the axial displacement of the nib. This displacement can be pressure-induced by movement of the nib toward the screen 12 by a user of the stylus to cause displacement of the nib against the resilient bias or by movement of the nib away from the screen under relaxation of the pressurable contact with the screen and consequently exposure of the nib to the restoring action of the resilient bias. The electrical value is preferably a voltage and particularly a signal amplitude directly correlated with audio volume.

The nib 15 of the stylus 13 is co-operable with the touch-sensitive surface of the screen 12 to cause an image of a mark, which is produced by contact of the end face of the protruding end of the nib with the touch-sensitive surface, to be displayed on the screen. If the nib is moved across the screen the mark extends into a line. The audio signal as varied by displacement of the nib as described in the foregoing is returned as an audio input to the processor 11 and reacted to by the processor software to influence, via the symbolic control line 21, the image instantaneously disp'ayed on the screen, in particular to change the size of the mark as a function of the signal variation. If the mark is extended to a line, the change in size is manifested as a change in width of the line. The electrically conductive construction or exterior of the nib allows co-operation with a resistive or capacitive touch-sensitive screen.

Fig. 2 is a schematic elevation of the stylus 13 showing the form it adopts as a handheld marking instrument and the disposition of the nib 15, potentiometer 16 and speaker 19 in the stylus body 14, as well as the paths of the connecting lines 22A to 22D. As shown, the resilient bias is produced by a shrouded helical compression spring 23 acting between, for example, a collar of the nib 15 and an annular seat on the body 14. The spring force of the spring 23 imparts tactility to the stylus operation. A cap 24 is provided to cover the nib when not in use. The lines 22A to 22D are connected with an external plug 25 insertable into the headphone-speaker/microphone socket of the processor 11.

The displacement of the nib 13, here in response to increase in pressure of contact with the screen 12, is shown in Figs. 3 and 4. Fig. 3 shows a fully extended state of the nib 15 and Fig. 4 a partly retracted state, i.e. state of displacement into the stylus body 14, with accompanying compression of the spring 23 and movement of the wiper 18 along the resistive member 17. As already indicated, return displacement of the nib 15 is produced by the restoring action of the spring under relaxation of the nib-to-screen contact pressure applied by the user.

The relationship of the size of a mark M, which is generated on the screen 12 by the nib 15, when axial displacement D of the nib takes place is illustrated in the two-dimensional graph of Fig. 5. Increasing displacement D as represented by the arrowed abscissa produces a change, here an increase, in the amplitude A of the audio signal as represented by the arrowed ordinate, which results in a progressively increasing size (diameter) of the mark M. Although discrete marks are depicted to demonstrate the increase in size, in practice the increase (and decrease) is continuous.

The pressure-induced displacement of the nib 15 may equally well be produced by direct manual actuation of the nib by a user, such as pressing the nib by a thumb while grasping the stylus body 14, in which case the stylus is capable of use as a control joystick subject to the presence of suitable software in the processor 11 Since the nib is not brought into contact with the screen to generate a mark, influencing of the image can then take the form of, for example, a predetermined movement of an image or image features, a predetermined dimensional change in an image or image feature, etc., depending on the image control by the software and the software response to the varied audio signal. The controller could conceivably be embodied exclusively as a joystick in which the nib functions solely as a button and possibly has a shape specifically adapted to that use.

The software app applied to the processor 11 may include software to provide a sound output at the speaker 19, for example music or oral instructions on how to use the stylus.

For example, the software may serve to guide a user through a learning process to teach proper use of the stylus or may be used in conjunction with, for example, a game or questions, in which case the stylus can then be used to answer the questions. These could be provided audibly by means of the speaker and a set of answers provided on the screen, in which case the stylus could be used to select the correct answer.

Claims

CLAIMS1. Apparatus comprising a processor with an output terminal and an input terminal for an audio signal, a controller for receiving an audio signal from the output terminal and returning the audio signal to the input terminal so as to be connected with the processor in an audio feedback loop, the controller comprising pressure-sensitive means responsive to change in pressure thereon to vary the audio signal as a function of the change, and a screen for displaying an image, the processor comprising control means responsive to the varied audio signal to influence the displayed image in dependence on the variation.
2. Apparatus according to claim 1, wherein the screen is a touch-sensitive screen and the pressure-sensitive means comprises a nib for causing generation of an image of a mark on the screen by contact of the nib with the screen, the nib being displaceable in response to change in the contact pressure between the nib and screen to vary the received audio signal and the control means being responsive to the varied audio signal to change the size of the mark in dependence, on the variation.
3. Apparatus according to claim 1, wherein the nib is movable across the screen to cause generation of an image of a line thereon and the control means is responsive to the varied audio signal to change the width of the line.
4. Apparatus according to claim 2 or claim 3, wherein the controller comprises a body and the nib is slidably mounted in and protrudes from the body.
5. Apparatus according to claim 4, wherein the nib is resiliently biased in a direction of maximum protrusion from the body.
6. Apparatus according to claim 4 or claim 3, wherein the controller has the form of a stylus.
7. Apparatus according to any one of the preceding claims, wherein the variation produced by the pressure-sensitive means is variation of a voltage.
8. Apparatus according to any one of the preceding claims, wherein the controller comprises variable impedance means for varying the audio signal and the pressure-sensitive means is displaceable to vary the impedance at the impedance means.
9. Apparatus according to claim 8, wherein the variable impedance means comprises a potentiometer.
10. Apparatus according to claim 9, wherein the potentiometer is a linear slider potentiometer.
11. Apparatus according to claim 9 or claim 10, wherein the pressure-sensitive means is fixed to a wiper of the potentiometer.
12. Apparatus according to any one of the preceding claims, wherein the controller comprises sound reproduction means to reproduce sound provided by a further audio signal from the processor.
13. Apparatus according to any one of preceding claims, wherein the variation of the audio signal is a variation of at least one of amplitude and frequency.
14. Apparatus according to any one of preceding claims, wherein the audio signal prior to variation thereof is of constant amplitude.
15. Apparatus according to any one of the preceding claims, wherein the controller has a wired connection with the output and input terminals and the audio signal is an electrical signal along the entire length of the feedback loop.
16. Apparatus according to any one of claims 1 to 14, wherein the controller has a wireless connection with the output and input terminals and the audio signal is a radio signal in the sections of the feedback loop between the processor and the controller.
17. Apparatus according to any one of the preceding claims, wherein the screen is integrated in the processor.
18. Apparatus according to any one of claims I to 16, wherein the processor and the screen are separate units.
19. Apparatus according to any one of the preceding claims, wherein the control means comprises software in the processor.
20. Apparatus according to any one of the preceding claims, wherein the pressure-sensitive means is manually displaceable by a user so that the controller is usable as a joystick.