GB2377014A

GB2377014A - Optical pointer device with switch

Info

Publication number: GB2377014A
Application number: GB0115818A
Authority: GB
Inventors: Thaddeus Halaczek; Andrew Watkins
Original assignee: Sendo International Ltd
Current assignee: Sendo International Ltd
Priority date: 2001-06-28
Filing date: 2001-06-28
Publication date: 2002-12-31
Anticipated expiration: 2021-06-28
Also published as: GB2377014B; GB0115818D0

Abstract

An optical pointer device comprises a translucent membrane 28 and a light-sensitive element 22 responsive to light passing through the translucent membrane 28. The optical pointer device also has a switch comprising a sensor 36 responsive to a predetermined threshold pressure applied to the membrane 28 so as to generate a switch signal.

Description

Optical Pointer Device with Switch The present invention relates to an optical pointer device with a switch.

Graphical User Interfaces (GUIs) are used in conjunction with many electronic machines such as PCs, personal organisers, mobile phones etc..

GUIs require means, such as a mouse or joy-pad, for allowing a user to cause a cursor or pointer to move on a display screen. Once the pointer has been positioned at the desired location, the user activates a function of the electronic machine by entering an input. For example, with a mouse, an option may be selected from a menu by positioning the pointer on a specified region of the screen and clicking a mouse button.

A problem arises with portable machines such as mobile phones, lap-top computers or personal organisers, where a mouse, joy-pad or similar device is impractical due to size or is cumbersome to use.

According to a first aspect of the present invention there is provided an optical pointer device with a switch, the optical pointer device comprising a translucent membrane, a light-sensitive element responsive to light passing through said translucent membrane, the switch comprising a sensor responsive to a predetermined threshold pressure applied to said membrane so as to generate a switch signal.

In a preferred embodiment the light-sensitive element is operative for generating a pattern signal comprising data relating to a pattern of light incident upon said light-sensitive element and a processor means is provided operative for controlling movement of a pointer on a display screen in response to

changes in said pattern signal, the processor means being further operative for generating an activation signal in response to said switch signal.

The pattern of light may be a pattern formed by reflection of light off a moveable control surface, for example a finger-tip, whereby movement of said control surface causes said changes in said pattern signal.

A light source directed towards the control surface may be provided to ensure sufficient intensity of light to facilitate detection of said pattern of light by said light-sensitive element. The light source may be an external light source, light from which is reflected off the control surface before passing through the translucent membrane.. Alternatively, the light source may be an internal light source, light from which passes through the membrane before being reflected back through the membrane off the control surface.

Embodiments of the invention facilitate movement of a pointer by a control surface, for example the tip of a user's finger, being moved across the membrane to change the pattern of light incident upon the light-sensitive element, and to facilitate entering of an input by exerting pressure on the membrane to activate the switch. Thus, the pointer device has no moving parts, the only movement being that of the user's finger (or other surface). Therefore, the device may be constructed with a membrane little larger than a finger-tip, and may be built into a machine such as a mobile phone or personal organiser.

Preferably, the membrane has a touch-surface for contact with the movable control surface, the touch-surface having a profile for aiding location and movement by the movable control surface.

The membrane may have a profile which acts as a lens for directing the reflected light towards the light-sensitive element.

Preferably, the light-sensitive element is contained within a housing, the membrane and housing together forming an enclosure, pressure applied to an exterior surface of the membrane activating the switch.

The light-sensitive element may comprise a single sensor element.

Alternatively, the light-sensitive element may comprise an array of sensor elements.

The light-sensitive element may be responsive to light passing through the membrane being transmitted through an optical system comprising one or more optical element such as a mirror or lens or prism.

An advantage of this arrangement is that it facilitates use of a lightsensitive element which provides greater resolution for detecting movement of the control surface.

The sensor may comprise a sensing electrode affixed to a surface of the membrane or embedded therein, and sensitive to pressure applied to the membrane.

Alternatively, the sensor may be a coating for the membrane, pressure applied to the membrane causing a change of an electrical parameter of the coating such as its resistance.

Alternatively, the membrane may comprise a translucent piezo-electric material operative for generating a change in a voltage across the membrane when a pressure is applied thereto.

According to a second aspect of the present invention there is provided a switch for an optical pointer device comprising a translucent membrane, a light-sensitive element responsive to light passing through said translucent membrane, the switch comprising a sensor responsive to a predetermined threshold pressure applied to said membrane so as to generate a switch signal.

Embodiments of the invention will be described by way of example having reference to the following drawings in which: Figure 1 shows a system diagram of a known electronic machine having a pointer device; Figure 2 shows a cross-section of a pointer device with a switch embodying the invention; and Figure 3 shows an alternative embodiment of a pointer device with a switch embodying the invention.

Referring to Figure 1, an electronic machine 8 has a display 10 and a machine processor 12 for carrying out programmed instructions in response to user inputs. For example, machine 8 may be a PC, a personal organiser or a mobile phone. A graphical user interface (GUI) comprises a pointer device 16, for allowing a user to control position of a cursor or other graphical pointer on the display. Pointer device 16 may be a mouse, joy-pad, rocker switch or other

pointing device. Activation of the pointer device 16 provides a signal to a GUI processor 18 which provides pointer movement data to the machine processor 12 for moving the position of the pointer on the display. An input means 20 in the form of a key, switch or button allows the user to generate an input signal (click).

Referring to Figure 2, a pointer device with a switch comprises a lightsensitive element 22 for generating a pattern signal in response to an incident pattern of light 24. Light-sensitive element 22 may comprise a single sensor element, or an array of sensor elements, the pattern signal comprising a plurality of signals from the sensors of the array. A housing 26 and a translucent membrane 28 form an enclosure around the light-sensitive element 22 so that only light passing through the membrane 28 is incident on the lightsensitive element 22. Light from an external source 30 is reflected off a control surface 32 before passing through the translucent membrane 28. The control surface 32 is provided with features 33 which reflect the light from the external source 30 to produce the pattern of light 24. The external light source 30 need not be a dedicated light source, but may be ambient light. However, the control surface 32 must be illuminated strongly enough for the energy of the light pattern 24 to be sensed by the light-sensitive element 22. A raised portion 34 of the translucent membrane provides a touch-surface for contact with the control surface 33, for aiding location and movement of the control surface 33 above the translucent membrane 28. The control surface 33 may be the user's finger-tip. In the embodiment of Figure 2, the raised portion 34 has a profile which acts as a lens, refracting the light reflected off the control surface 32, and directing it towards the light-sensitive element.

A switch comprises a sensor 36 attached to the underside of the translucent membrane 28 and passing through the housing 26. The sensor 36 is responsive to a predetermined threshold pressure applied to the translucent membrane 28 so as to generate a switch signal.

The sensor 36 may be a sensing electrode affixed to the surface of the membrane 28, and sensitive to an applied force caused by pressure applied to the membrane28 to change an electrical parameter of the electrode, for example its resistance.

Alternatively, the sensor 36 may be a coating applied to the membrane 28 and sensitive to pressure applied by change of an electrical parameter such as its resistance.

Alternatively, the membrane 28 may comprise a translucent piezoelectric material. Pressure applied to the membrane 28 causes a change in a voltage across the membrane.

In use, the user moves the control surface 32 so as to change the pattern of light 24 incident on the light-sensitive element 22. The pattern signal generated by the light-sensitive element changes and is read by the GUI processor 18 of Figure 1. GUI processor 18 interprets the change in the pattern signal and provides data to the machine processor 12 for moving the location of the cursor on the display 10.

When the user requires to provide an input (click), pressure is applied by the control surface 33 to the translucent membrane 28. The pressure is sensed by the sensor 36 and, provided the pressure is above the predetermined

threshold a switch signal is generated. The switch signal is read by the GUI processor 18 of Figure 1, which provides the input data to the machine processor 12.

Referring to Figure 3, in an alternative embodiment where corresponding features have identical reference numerals, a light source 38 is situated below the translucent membrane 28 so that light passes through the translucent membrane 28 before being reflected back through the translucent membrane 28 off the control surface 32. The reflected light pattern 24 is further reflected by a mirror 40 and passes through a lens 42 for providing a focussed pattern 44 incident on the light-sensitive element 22. Thus the lightsensitive element 22 is situated at the end of a light path through an optical system. The optical system (mirror 40 and lens 42) facilitates use of a lightsensitive element 22 which provides greater resolution for detecting movement of the control surface 32. It will be appreciated that alternative optical systems may be employed featuring arrangements that might include one or more mirror, lens, prism or other optical component.

Claims

Claims 1. An optical pointer device with a switch, the optical pointer device comprising a translucent membrane, a light-sensitive element responsive to light passing through said translucent membrane, the switch comprising a sensor responsive to a predetermined threshold pressure applied to said membrane so as to generate a switch signal.
2. An optical pointer device according to claim 1 wherein the lightsensitive element is operative for generating a pattern signal comprising data relating to a pattern of light incident upon said light-sensitive element and a processor means is provided operative for controlling movement of a pointer on a display screen in response to changes in said pattern signal, the processor means being further operative for generating an activation signal in response to said switch signal.
3. An optical pointer device according to claim 2 wherein the pattern of light is a pattern formed by reflection of light off a moveable control surface, for example a finger-tip, whereby movement of said control surface causes said changes in said pattern signal.
4. An optical pointer device according to claim 3 wherein a light source directed towards the control surface is provided to ensure sufficient intensity of light to facilitate detection of said pattern of light by said light-sensitive element.

<Desc/Clms Page number 9>
5. An optical pointer device according to claim 4 wherein the light source is an external light source, light from which is reflected off the control surface before passing through the translucent membrane.
6. An optical pointer device according to claim 4 wherein the light source is an internal light source, light from which passes through the membrane before being reflected back through the membrane off the control surface.
7. An optical pointer device according to any one of claims 3 to 6 wherein the membrane has a touch-surface for contact with the movable control surface, the touch-surface having a profile for aiding location and movement by the movable control surface.
8. An optical pointer device according to any one of claims 3 to 7 wherein the membrane has a profile which acts as a lens for directing the reflected light towards the light-sensitive element.
9. An optical pointer device according to any preceding claim wherein the light-sensitive element is contained within a housing, the membrane and housing together forming an enclosure, pressure applied to an exterior surface of the membrane activating the switch.
10. An optical pointer device according to any preceding claim wherein the light-sensitive element comprises a single sensor element.
11. An optical pointer device according to any one of claims I to 7 wherein the light-sensitive element comprises an array of sensor elements.

<Desc/Clms Page number 10>
12. An optical pointer device according to any preceding claim wherein the light-sensitive element is responsive to light passing through the membrane being transmitted through an optical system comprising one or more optical element such as a mirror or lens or prism.
13. A switch for an optical pointer device comprising a translucent membrane, a light-sensitive element responsive to light passing through said translucent membrane, the switch comprising a sensor responsive to a predetermined threshold pressure applied to said membrane so as to generate a switch signal.
14. An optical pointer device according to any one of claims 1 to 12, or a switch according to claim 13 wherein the sensor comprises a sensing electrode affixed to a surface of said membrane or embedded therein, and sensitive to pressure applied to the membrane.
15 An optical pointer device according to any one of claims 1 to 12, or a switch according to claim 13 wherein the sensor is a coating for the membrane, pressure applied to the membrane causing a change of an electrical parameter of the coating such as its resistance.
16. An optical pointer device according to any one of claims 1 to 12, or a switch according to claim 13 wherein the membrane comprises a translucent piezo-electric material operative for generating a change in a voltage across the membrane when a pressure is applied thereto.
17. An optical pointer device with a switch as shown in the drawings of Figure 2 or Figure 3.