WO2012032480A1

WO2012032480A1 - Pointing device with reduced height

Info

Publication number: WO2012032480A1
Application number: PCT/IB2011/053916
Authority: WO
Inventors: Steven Wang; Leslie Scenna
Original assignee: Contour Design, Inc.; Andersson, Björn
Priority date: 2010-09-07
Filing date: 2011-09-07
Publication date: 2012-03-15
Also published as: SE1350370A1; SE1050995A1; SE536956C2; SE1351367A1; SE538345C2; EP2614419A1

Abstract

A pointing device has a housing (110) having a base (112). The pointing device also has a rollerbar assembly (120) comprising a rollerbar (122) and a rollerbar bracket (130). The rollerbar bracket supports rotation and translation of the rollerbar, and the rollerbar assembly is depressible with respect to the base. Sensor means (170) is provided for detecting movement of the rollerbar. The pointing device further has a leaf spring (190) having a first end (192) mounted to the base and a second end (194) positioned below the rollerbar bracket (130) to counteract a click force required to depress the rollerbar assembly (120). Adjustment means (200) is provided for controlling the counteraction provided by the leaf spring.

Description

POINTING DEVICE WITH REDUCED HEIGHT

Technical Field

The present invention generally relates to computer accessories, and more specifically to a pointing device for controlling the user interface of a computer.

Background

Personal computers are available in many different brands, sizes and types. The first generations of personal computers had limited processing power and graphic display capabilities. A keyboard was typically the only type of computer accessory used as user input device for those early personal computers. The keyboard is still a dominating user input device for personal computers because of its feasibility for massive input of text. In addition, with the advent of graphical user interfaces (GUI), pointing devices have become and remain a very common type of computer accessory. Within the context of the present disclosure, a pointing device is a computer accessory adapted for allowing a computer user to control the position of a cursor in graphical user interface, as well as to perform relation actions such as selection of an object presented in the graphical user interface. The computer mouse is probably the most known example of such a pointing device. Other known examples include a trackball, a joystick, and a touchpad.

From the many years that computer mice have been in widespread use it has become apparent that the usage is associated with various drawbacks. Several of those drawbacks relate to user ergonomics. One example of an ergonomic drawback of heavy usage of a computer mouse is neck, shoulder or elbow pain caused by asymmetric computer mouse reaching with one side of the body but not the other. The root of this problem is that the computer mouse is designed to be located and operated laterally either to the right or to the left of the keyboard.

Other frequent ergonomic problems that appear among many computer mouse users are repetitive strain injuries, such as carpal tunnel syndrome or tendonitis. These problems are believed to be caused by the gripping of the hand and flexing of the fingers upon the computer mouse.

Ergonomic pointing devices have therefore been developed as replacement of conventional computer mice. The intended assignee of this patent application, Contour Design, Inc., has taken the leadership in the development of ergonomic pointing devices which have been successfully sold for a number of years under the trademark RollerMouse . PCT publication WO 02/043046 presents some earlier versions of RollerMouse^® pointing devices.

The basic design of RollerMouse^® pointing devices includes a housing which has a base and an upper cover. The housing is designed to be placed adjacently to the lower lateral edge of the keyboard on a desktop surface or similar. (For a common QWERTY-type keyboard, the lower later edge is the edge just below the row of keys that includes the elongate space bar). A rollerbar is provided in an opening of the upper cover. By rotating the rollerbar around its central axis and translation (sliding) it along the central axis, the user of a RollerMouse^® pointing device may control the x and y coordinates of the cursor location in a graphical user interface of a computer to which the RollerMouse^® pointing device is connected. Thus, the rollerbar acts as a cursor navigation bar. To this end, the RollerMouse^® pointing device has a built-in optical sensor capable of detecting the rotation and translation of the rollerbar, and controller means in the form of electronic circuitry capable of transmitting data regarding the detected rollerbar movement as cursor control signals to the computer. Furthermore, the rollerbar is designed to be depressible by the user, thereby allowing him to perform actions corresponding to conventional mouse clicks. In addition to the rollerbar, the upper cover of the RollerMouse^® pointing device has a set of buttons representing common mouse-related actions such as left-click, right-click, double-click, etc.

As a result, the user may ergonomically operate the RollerMouse^® pointing device to get full access to all mouse-related actions with only small hand and finger movements, using his right or left hand, or both hands, at his discretion. At the same time, since the RollerMouse^® pointing device is located immediately below the keyboard, the user will be able to reach the keys of the keyboard with only minimum hand movements between the RollerMouse^® pointing device and the keyboard. All in all, RollerMouse^® pointing devices have proven effective in reducing ergonomic problems normally associated with computer cursor control.

The present inventors have realized that there is still room for certain improvements in view of the problems referred to above. A first problem addressed by the present inventors is the ergonomic importance of the rollerbar's vertical position - i.e. the vertical distance between the desktop surface that the pointing device is placed and the uppermost surface of the rollerbar. More specifically, the present inventors have realized that the movement of the user's hands back and forth between the rollerbar of the pointing dev ice and the keys of the adjacent keyboard should be allowed to be carried out with as little lifting or lowering of the hands as possible. A second problem addressed is that computer keyboards come in many different sizes and types. In particular, there may be substantial differences in vertical height between different types of keyboards.

A third problem addressed by the present inventors is the risk of accidental cursor travel when the roUerbar is depressed. Such accidental cursor travel may be caused by unintentional rotation of translation of the roUerbar as it is being depressed, or by misinterpretation by the optical sensor of the roUerbar' s depressive movement as a rotational of translational movement, or by a combination of these factors. Summary

It is accordingly an object of the invention to eliminate or alleviate at least some of the problems referred to above.

As a conceptual idea behind the invention, the present inventors have realized that there are at least three inventive design measures that can be implemented, either in isolation or in combination, for a rollerbar-type pointing device.

A first of these inventive design measures relates to an adjustable click force arrangement. A second of these inventive design measures involves the provision of a kit of parts including adjustable keyboard risers which serve to raise the adjacent keyboard vertically to level with the roUerbar. A third of these inventive design measures involves a roUerbar assembly including a roUerbar and a roUerbar bracket carrying both the roUerbar and the sensor, wherein the sensor is mounted at an angle to horizontal and in a fixed position with respect to the roUerbar bracket, such that the sensor and the ro erbar move together when the roUerbar assembly is depressed.

One aspect of the present invention therefore is a pointing device comprising: a housing, said housing having a base;

a roUerbar assembly comprising a roUerbar and a roUerbar bracket, wherein the roUerbar bracket is configured to support rotation and translation of said roUerbar, and wherein the roUerbar assembly is depressible with respect to said base;

sensor means for detecting movement of said roUerbar;

a leaf spring having a first end mounted to said base and a second end positioned below said roUerbar bracket and configured to counteract a click force required to depress said roUerbar assembly, and

adjustment means for controlling the counteraction provided by said leaf spring. A second aspect of the invention is a pointing device of the type having a housing with an edge adapted to be positioned facing a computer keyboard, the pointing device comprising:

one or more first-type keyboard risers, the or each first-type keyboard riser being adapted for engagement with said housing at said keyboard- facing edge, and the or each first-type keyboard riser having a support surface adapted to provide a first vertical support height for said computer keyboard; and

one or more second-type keyboard risers, the or each second-type keyboard riser being adapted for engagement with a respective one of said one or more first-type keyboard risers, the or each second-type keyboard riser having a support surface adapted to provide a second vertical support height for said computer keyboard.

A third aspect of the invention is a kit of accessory parts for a pointing device according to the second aspect of the invention, the kit of accessory parts comprising one or more first-type keyboard risers and one or more second-type keyboard risers as defined above for the second aspect of the invention.

A fourth aspect of the invention is a pointing device comprising:

a housing, said housing having a base with a horizontal extension;

a rollerbar assembly comprising a rollerbar and a rollerbar bracket, wherein the rollerbar bracket is configured to support rotation and translation of said rollerbar, and wherein the rollerbar assembly is depressible with respect to said base; and

sensor means for detecting movement of said rollerbar, said sensor means comprising an optical sensor having a light receiving surface and being capable of detecting rotational and translational movement of said rollerbar,

wherein the optical sensor is disposed in said housing in a fixed position with respect to said rollerbar bracket, such that the light receiving surface is arranged at an angle with respect to the horizontal extension of said base, and such that the optical sensor is arranged to move together with said rollerbar bracket when the rollerbar assembly is depressed.

Even though the preferred embodiment, which is described in detail below with reference to the drawings, implements all of the first, second, third and fourth aspects of the invention, it is expressly stated that the first aspect of the invention can be implemented in or as a pointing device that does not necessarily implement any of the second to fourth aspects of the invention, or it can be implemented in or as a pointing device that also implements any or all of the second to fourth aspects of the invention. Correspondingly, the second and third aspects of the invention can be implemented in or as a pointing device that does not necessarily implement any of the first or fourth aspects of the invention, or it can be implemented in or as a pointing device that also implements any or all of the first and fourth aspects of the invention.

Moreover, the fourth aspect of the invention can be implemented in or as a pointing device that does not necessarily implement any of the first to third aspects of the invention, or it can be implemented in or as a pointing device that also implements any or all of the first to third aspects of the invention. Brief Description of the Drawings

Objects, features and advantages of a preferred embodiment of the invention will appear from the following detailed description, reference being made to the accompanying drawings.

Fig 1 is a perspective view of a pointing device according to preferred the embodiment of the present invention, having in this case a pair of mini keyboard risers attached to the device housing.

Fig 2 is a perspective view of the pointing device, having a pair of keyboard risers attached to the mini keyboard risers.

Fig 3 is a side view of the pointing device in Fig 1, showing more clearly one of the mini keyboard risers.

Fig 4 is a side view of the pointing device in Fig 2, showing more clearly one of the keyboard risers in a folded-down position.

Fig 5 is a side view of the pointing device in Fig 2, showing more clearly one of the keyboard risers in a first lifted-up position.

Fig 6 is a side view of the pointing device in Fig 2, showing more clearly one of the keyboard risers in a second lifted-up position.

Fig 7 is a perspective view of the pointing device, a cover of the pointing device's housing being removed to disclose internal components of the pointing device.

Fig 8 is a perspective view of the underside of the pointing device in Fig 1. Fig 9 is a top plan view of the pointing device.

Figs 10-13 are views which are taken along the section A- A in Fig 9 and which illustrate the action of a click force adjustment slider in different settings for light and heavy click force required for depressing a rollerbar assembly in the pointing device.

Fig 14 is a sectional plan view of the pointing device. Fig 15 is a view which is taken along the section B-B in Fig 14 and which illustrates, inter alia, the location of a click switch for detecting depression of the rollerbar assembly in the pointing device.

Fig 16 is a perspective view of the pointing device's rollerbar assembly.

Fig 17 is a top plan view of the rollerbar assembly shown in Fig 16.

Fig 18 is a simplified view, taken along the section A-A in Fig 17, of the rollerbar assembly, illustrating the location of an optical sensor for detecting rotational and translational movement of the rollerbar. Detailed Description

The preferred embodiment of the invention will now be described with reference to the accompanying drawings. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiment set forth herein; rather, this embodiment is provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. The terminology used in the detailed description of the particular embodiment illustrated in the accompanying drawings is not intended to be limiting of the invention. In the drawings, like numbers refer to like elements.

Fig 1 is a perspective view of a pointing device 100 according to preferred the embodiment of the present invention. The pointing device 100 is designed to act as an ergonomic substitute for a conventional computer mouse and thus has an interface, such as a serial USB interface, for connection to a computer. Only a keyboard 99 of the computer is shown in Fig 1. The pointing device 100 includes a housing 110 which has a base 112 and an upper cover 114, consisting mainly of three larger parts: a left cover part 115, a center cover part 116 and a right cover part 117. The housing is designed to be placed with one edge 100a or lateral side being located immediately adjacently to the lower lateral edge 99a of the keyboard 99. When the keyboard 99 is a QWERTY-type keyboard, the lower later edge 99a is just below a first row of keyboard keys which include an elongate space bar 98.

A rollerbar 122, or cursor navigation bar, is provided in an opening in the upper cover 114. The rollerbar 122 is part of a depressible rollerbar assembly 120, which will be described in more detail later. By rotating the rollerbar 122 around its central axis and translation (sliding) it along the central axis, the user of the pointing device 100 may control the x and y coordinates of the cursor location in a graphical user interface of the computer to which the pointing device 100 is connected. A built-in optical sensor (seen at 170 in Fig 18) detects the rotation and translation of the rollerbar 122, and controller means in the form of electronic circuitry (seen schematically at 182 in Fig 18) is associated with the optical sensor and transmits data regarding the detected rollerbar movements as cursor control signals to the computer. Correspondingly, a click sensor (seen at 220 in Fig 15) detects depressions of the rollerbar assembly 120, and the controller means transmits data regarding the detected rollerbar depressions as mouse click or select control signals to the computer.

In addition to the depressible rollerbar assembly 120, the user has access to a set of buttons 140 which are provided in the center cover part 116 of the housing 110 and which represent common mouse-related actions. A first button 141 emulates a mouse left-click action and therefore represents an alternative to depressing the rollerbar assembly 120. A second button 142 emulates a mouse right-click action. A third button 143 triggers a mouse double-click action from a single one-touch actuation. A fourth button 144 is a scroll lock button. A fifth button 145 is a drag lock button which may be used for one-touch copy & paste operations. A scroll wheel 146 may be used for scrolling text or other contents presented in the graphical user interface of the computer.

As will be clear from the description in later sections of this document, the pointing device 100 has been designed to have a reduced height. A number of design steps have been taken to achieve this. For instance, the rollerbar assembly has been designed to include a rollerbar bracket which supports the rollerbar for rotation and translation, and acts as an angled mounting support for the optical sensor, such that the optical sensor is arranged at a non-horizontal angle and moves together with the rollerbar bracket when the rollerbar assembly is depressed. A leaf spring with adjustable spring force supports the rollerbar bracket from below and serves to establish an appropriate click force for depressing the rollerbar assembly, adjustable to the user's individual needs. This arrangement allows the pointing device to be implemented with a reduced height compared to prior art devices, and at the same time minimizes the risk of cursor travel.

To adapt the pointing device 100 for use with keyboards 99 of different sizes and types, in particular having substantial differences in height, a kit of accessory parts in the form of a set of keyboard risers is provided. As seen in Figs 1 and 2, the set of keyboard risers includes one or more first-type keyboard risers 1 0 and one or more second-type keyboard risers 160. In the disclosed embodiment, there are two first-type keyboard risers 150, also referred to as mini keyboard risers 150, and two second-type keyboard risers 160, also referred to simply as keyboard risers 160. As seen more clearly in Fig 3, the mini keyboard risers 150 are adapted for engagement with the housing 110 at the keyboard-facing edge 100a of the pointing device 100, and they each have a support surface 158 which provides a first vertical support height hi for the computer keyboard 99. Each mini keyboard riser 150 has feet 152 at its underside, serving to maintain the mini keyboard riser, and the keyboard supported thereon, in a steady position on the desktop surface. Each mini keyboard riser 150 also has recesses 154 for securing a respective second-type keyboard riser 160, when attached.

As seen in Fig 2 and Figs 4-6, the keyboard risers 160 are adapted for engagement with respective ones of the mini keyboard risers 150 by snapping on top of the latter. Each keyboard riser 160 has a support surface 168 adapted to provide a second vertical support height h₂ for the computer keyboard 99. The user may adapt his pointing device 100 for use with keyboard of different heights in the following manner.

If only the mini keyboard risers 150 are used, as seen in Fig 3, they will provide the first vertical support height hi for a front part of the computer keyboard 99, i.e. at the keyboard edge 99a proximate to the pointing device 100. This is because the mini keyboard risers 150 are fairly short in length. The first vertical support height hi may for instance be 5.4 mm, or more generally in the range of 4-6 mm, but other values are also possible.

If on the other hand the keyboard risers 160 are used, they will support also other parts of the keyboard 99, distant from the proximal edge 99a. The reason is that the keyboard risers 160 are substantially longer than the mini keyboard riser 150. The keyboard risers 160 are adjustable in height, as is illustrated in Figs 4-6.

When the keyboard risers 160 are mounted onto the mini keyboard 150 in a folded-down position as seen in Fig 4, the second vertical support height h₂ will be provided along the entire length of the keyboard risers 160. The second vertical support height h₂ may for instance be 10.9 mm, or more generally in the range of 7-12 mm, but other values are also possible.

Each keyboard riser 160 has a front end 161 positioned proximate to the keyboard- facing edge 100a of the pointing device 100, a rear end 163, and an intermediate part 162 positioned between the front end 161 and rear end 163. Both the front end 161 and the rear end 163 are adjustable in height. As seen in Fig 5, the keyboard riser 160 has means 165, 166 in the form of a hinged leg for raising the rear end 163 to provide a third vertical support height 1¾ for the distal part of the computer keyboard 99. The third vertical support height 1¾ may for instance be 17.9 mm, or more generally in the range of 13-20 mm, but other values are also possible. As seen in Fig 6, each keyboard riser 160 also has means 161, 162, 164 for raising the intermediate part 162 to provide a fourth vertical support height I14 for the computer keyboard 99. This is possible since the intermediate part 162 is hinged at 164 to the front end 161. The fourth vertical support height is provided when the intermediate part 162 is pivotally lifted up onto the upper surface of the front end 161. The fourth vertical support height 14 may for instance be 17.1 mm, or more generally in the range of 13-20 mm, but other values are also possible.

An adjustable click force arrangement for the roUerbar assembly 120 will now be described with reference to Figs 7-18. As seen particularly in Fig 7 and 16-18, the roUerbar assembly 120 comprises a roUerbar bracket 130, which is configured to support rotation and translation of the roUerbar 120. To this end, the roUerbar 122 consists on an inner metal bar 128 having two ends 128a-b which is supported between first and second ends 130a-b of the roUerbar bracket 130. A roUerbar sleeve or tube 124 is rotatably and slidably mounted around the inner metal bar 128 by means of two bearings 126. The roUerbar bracket 130 is pivotally mounted to the base 112 at pivot points 132a-b to support depression of the roUerbar assembly 120 with respect to the base 112. The roUerbar bracket 130 is made from a formed thin steel sheet metal which is bent to add strength to the roUerbar assembly 120.

A leaf spring 190 (Figs 9-10) is provided which has a first end 192 mounted to the base 112 and a second free end 194 positioned below the roUerbar bracket 130. In an unloaded state in which the roUerbar assembly 120 is not depressed, the second end 194 of the leaf spring 190 is configured to engage with and lift the roUerbar bracket 130 at a central position remote from the first and second ends 130a-b of the roUerbar bracket 130. The leaf spring 190 has an inherent spring force and is thus also configured to counteract the click force required to depress the roUerbar assembly 120. The required click force is the force that the user needs to apply onto the roUerbar assembly 120 to overcome the counteraction provided by the leaf spring 190 and actuate the click sensor 220 (Fig 15).

Adjustment means 200 are provided for controlling the counteraction provided by the leaf spring 190. As seen in for instance Fig 10, the leaf spring 190 has a longitudinal extension between the first and second ends 192, 194. The adjustment means 200 comprises a click force adjustment slider 200 having a leaf spring support element 202 for supporting engagement with the leaf spring 190. The click force adjustment slider is displaceable in the direction of the longitudinal extension of the leaf spring 190 for setting the position 203 in which the leaf spring support element 202 engages the leaf spring 190.

A user desiring to set the click force of the rollerbar assembly 120 may use an actuator element 204 of the click force adjustment slider 200. The actuator element 204 is accessible from an underside 113 of the base 112, as seen in Fig 8. By sliding the actuator element 204, the user may change the engagement position 203 of the leaf spring support element 202 along the extension of the leaf spring 190, thereby changing the effective spring force provided by the leaf spring 190. Figs 10 and 11 show the click force adjustment slider 200 in a first position for weaker click force, where only a lighter depression of the rollerbar assembly 120 is required to overcome the counteraction provided by the leaf spring 190 and actuate the click switch 220. Fig 10 represents the unloaded state with no depression of the rollerbar assembly 120, whereas Fig 11 represents a depressed state where the rollerbar assembly 120 has been depressed and the click switch 220 is actuated.

Correspondingly, Figs 12 and 13 show the click force adjustment slider 200 in a second position for stronger click force, where a harder depression of the rollerbar assembly 120 is required to overcome the counteraction provided by the leaf spring 190 and actuate the click switch 220. The click force adjustment slider 200 is displaceable to an arbitrary number of other positions to select other click force settings at the user's discretion.

The design and configuration of the rollerbar assembly 120 with respect to the optical sensor 170 in order to allow a reduced device height and minimize accidental cursor travel will now be described with reference to Figs 16-18. As seen in Fig 18, the sensor means 170 comprises an optical sensor 170 for the purpose of detecting rotational and translational movement of the rollerbar 122. The optical sensor is disposed in the housing 110 in a fixed position with respect to the rollerbar bracket 130 and is arranged to move together with the rollerbar bracket when the rollerbar assembly 120 is depressed and pivots around the pivot points 132a-b. The optical sensor 170 comprises a light emitter 172, such as a laser LED, and a light receiving surface 174 capable of detecting light reflected back from the rollerbar tube 124. The optical sensor 170 is soldered onto a printed circuit board 180, and the printed circuit board is mounted to a bent part 139 of the rollerbar bracket 130. This means that the light receiving surface 174 of the optical sensor 170 is arranged at an angle a with respect to the horizontal extension of the base 112. The angle a may be about 45°, or smaller or larger on other embodiments. Mounting the optical sensor 170 at an angle to horizontal preserves vertical distance and allows the pointing device 100 to be designed with a reduced height. Also, the fixed mounting of the optical sensor with respect to the rollerbar bracket 130 will mean that there will be no relative movement between these elements when the rollerbar assembly 120 is depressed. In effect, the risk for accidental cursor travel is reduced.

As already mentioned the controller means in the form of electronic circuitry 182 is associated with the optical sensor 170 and is configured to transmit data regarding the detected rollerbar movements as cursor control signals to the computer. The controller means 182 may also be associated with the click sensor 220 (Fig 15) and may be configured to transmit data regarding the detected rollerbar depressions as control signals to the computer. It is to be noticed that the location of the controller means 182 does not have to be the one which is schematically illustrated in Fig 18.

The invention has been described above in detail with reference to the preferred embodiment thereof. However, as is readily understood by those skilled in the art, other embodiments are equally possible within the scope of the present invention, as defined by the appended claims.

Claims

1. A pointing device comprising:

a housing (110), said housing having a base (112);

a rollerbar assembly (120) comprising a rollerbar (122) and a rollerbar bracket

(130), wherein the rollerbar bracket is configured to support rotation and translation of said rollerbar, and wherein the rollerbar assembly is depressible with respect to said base;

sensor means (170) for detecting movement of said rollerbar;

characterized by

a leaf spring (190) having a first end (192) mounted to said base and a second end (194) positioned below said rollerbar bracket (130) and configured to counteract a click force required to depress said rollerbar assembly (120), and

adjustment means (200) for controlling the counteraction provided by said leaf spring.

2. A pointing device according to claim 1, wherein the second end (194) of said leaf spring (190) is configured to engage with and lift the rollerbar bracket (130) in an unloaded state in which the rollerbar assembly (120) is not depressed.

3. A pointing device according to claim 1 or 2, the leaf spring (190) having a longitudinal extension between said first and second ends (192, 194), wherein the adjustment means (200) comprises a click force adjustment slider (200) having a leaf spring support element (202) for supporting engagement with the leaf spring (190), and wherein the click force adjustment slider is displaceable in the direction of the longitudinal extension of the leaf spring for setting the position in which the leaf spring support element engages the leaf spring.

4. A pointing device according to claim 3, the base (112) of the housing (110) having an underside (113), wherein the click force adjustment slider (200) has an actuator element (204) which is accessible from the underside of said base for a user desiring to set the click force of said rollerbar assembly (120).

5. A pointing device according to any of claims 2-4, the rollerbar (122) being supported between first and second ends (130a, 130b) of said rollerbar bracket (130), wherein the leaf spring (190) is mounted to said base (112) such that the second end (1 4) of the leaf spring engages the rollerbar bracket (130) at a central position remote from said first and second ends of said rollerbar bracket.

6. A pointing device according to any of the preceding claims, said housing

(110) having an edge (100a) adapted to be positioned facing a computer keyboard (99), the pointing device further comprising:

one or more first-type keyboard risers (150), the or each first-type keyboard riser being adapted for engagement with said housing at said keyboard-facing edge (100a), and the or each first-type keyboard riser having a support surface (158) adapted to provide a first vertical support height (hi) for said computer keyboard; and

one or more second-type keyboard risers (160), the or each second-type keyboard riser being adapted for engagement with a respective one of said one or more first-type keyboard risers (150), the or each second-type keyboard riser having a support surface (168) adapted to provide a second vertical support height (h₂) for said computer keyboard.

7. A pointing device according to claim 6, wherein the or each first-type keyboard riser (150) has a first length adapted such that the first vertical support height (hi) is provided for a front part of said computer keyboard (99), said front part being proximate to said pointing device.

8. A pointing device according to claim 7, wherein the or each second-type keyboard riser (160) has a second length, longer that said first length, said second length being adapted such that the second vertical support height (1_¾) is provided for a non- front part of said computer keyboard, distant from the front part thereof.

9. A pointing device according to claim 8, wherein the or each second-type keyboard riser (160) has a front end (161) positioned proximate to said keyboard- facing edge (100a) and a rear end (163), the or each second-type keyboard riser having means (165, 166) for raising its rear end to provide a third vertical support height (]¾) for the non- front part of said computer keyboard (99).

10. A pointing device according to claim 9, wherein the or each second-type keyboard riser (160) has an intermediate part (162) positioned between said front end (161) and said rear end (163), and comprises means (161, 162, 164) for raising the intermediate part (162) to provide a fourth vertical support height (I14) for the computer keyboard (99).

11. A pointing device according to any of the preceding claims, wherein the sensor means (170) comprises an optical sensor (170) capable of detecting rotational and translational movement of said rollerbar (122), wherein the optical sensor is disposed in said housing (110) in a fixed position with respect to said rollerbar bracket (130) and is arranged to move together with said rollerbar bracket when the rollerbar assembly is depressed.

12. A pointing device according to claim 11, said base (112) having a horizontal extension, said optical sensor (170) having a light receiving surface (174), wherein said optical sensor is attached to said rollerbar bracket (130) such that the light receiving surface is arranged at an angle (a) with respect to the horizontal extension of said base.

13. A pointing device according to claim 11 or 12, wherein the optical sensor (170) is soldered onto a printed circuit board (180) and wherein the printed circuit board is mounted to said rollerbar bracket (130).

14. A pointing device according to any of the preceding claims, further comprising controller means (182) associated with said sensor means (170), said controller means being adapted for transmitting data to a computer regarding movement of said rollerbar (122).

15. A kit of accessory parts for a pointing device (100) of the type having a housing (110) with an edge (100a) adapted to be positioned facing a computer keyboard (99), the kit of accessory parts comprising:

one or more first-type keyboard risers (150), the or each first-type keyboard riser being adapted for engagement with the housing of said pointing device (100) at said keyboard- facing edge (100a), and the or each first-type keyboard riser having a support surface (158) adapted to provide a first vertical support height (hi) for said computer keyboard; and one or more second-type keyboard risers (160), the or each second-type keyboard riser being adapted for engagement with a respective one of said one or more first-type keyboard risers (150), the or each second-type keyboard riser having a support surface (168) adapted to provide a second vertical support height (1¾) for said computer keyboard.

16. A kit of accessory parts according to claim 15, wherein the or each first- type keyboard riser (150) has a first length adapted such that the first vertical support height (hi) is provided for a front part of said computer keyboard (99), said front part being proximate to said pointing device.

17. A kit of accessory parts according to claim 16, wherein the or each second- type keyboard riser (160) has a second length, longer that said first length, said second length being adapted such that the second vertical support height (h₂) is provided for a non- front part of said computer keyboard, distant from the front part thereof.

18. A kit of accessory parts according to claim 17, wherein the or each second- type keyboard riser (160) has a front end (161) positioned proximate to said keyboard- facing edge (100a) and a rear end (163), the or each second-type keyboard riser having means (165, 166) for raising its rear end to provide a third vertical support height (1¾) for the non- front part of said computer keyboard (99).

1 . A kit of accessory parts according to claim 18, wherein the or each second- type keyboard riser (160) has an intermediate part (162) positioned between said front end (161) and said rear end (163), and comprises means (161, 162, 164) for raising the intermediate part (162) to provide a fourth vertical support height (I14) for the computer keyboard (99).