WO2001023984A1

WO2001023984A1 - Computer with a pen or touch sensitive display

Info

Publication number: WO2001023984A1
Application number: PCT/GB2000/003698
Authority: WO
Inventors: Martin Philip Riddiford
Original assignee: Psion Computers Plc
Priority date: 1999-09-28
Filing date: 2000-09-27
Publication date: 2001-04-05
Also published as: GB9922910D0

Abstract

A computer with a touch sensitive and/or pen sensitive display, in which the position of the fully opened display is such that the torque typically applied by a finger or a pen to the top most pen or touch sensitive part of the display, in relation to a rotational axis about which the computer would rotate if it were to tip backwards, is less than that needed to cause the computer to tip backwards about that rotational axis, and including a keyboard fixed to a first portion of a base of the computer and further including a second, rear portion of the base that is caused to move automatically rearwards relative to the first portion of the base as the display is opened.

Description

Computer with a Pen or Touch Sensitive Display

Field of the Invention

This invention relates to computers with a pen and/or touch sensitive display, for example palmtop and notebook computers running a pen and/or touch enabled operating system. The term 'computer' should be expansively construed to cover any micro-processor controlled device with a display, and hence covers devices such as communicators and smart phones.

Description of the Prior Art

In portable computer design, one typically wants to include a large display, yet keep the overall size of the computer as compact as possible. Successfully reconciling these two requirements is one of the more difficult problems facing the designer of portable computers. There are two well established solutions to this problem: Conventional portable computers, such as PDAs (Personal Digital Assistants), palmtops, sub-notebooks and notebooks, generally use either a tablet or a clam shell design. An example of a tablet design is the Apple Newton PDA from Apple Computers, Inc. In a tablet, the computer is a one-piece unit with a display occupying much of the upper surface. In the clam shell design, the display is usually hinged at or near the rear of the computer. The clam shell approach is used in the Psion Series 3a palmtop from Psion Computer pic and virtually all sub- notebooks and notebooks. Both approaches enable a display that occupies much of the footprint of the device to be used.

The clam shell approach can bring its own problems: in early notebook designs (for example in the late 1980s), the display was far heavier than it is in today's machines. That was in large part because of the relatively thick glass used at that time and the kind of display technology used. US 4,960,256 to Sony Corporation from 1988 notes that some clam shell notebooks can tip backwards after the display has been opened up for viewing. That happens when a vertical line drawn through the center of gravity of the computer does not fall within the base of the computer but instead falls to the rear of and outside of the computer. The Sony patent teaches a hinge that enables the lower edge of the display to slide forwards when the display is opened up for viewing. Moving the base of the display forwards in this manner ensures that the centre of gravity of the computer does not shift backwards when the display is fully opened so much that the computer tips backwards.

The Sony patent does not however relate to a computer with a pen or touch sensitive display. There are now however numerous PDAs with clam shell designs that include pen sensitive displays. These PDAs include the Philips Velo and various palmtops from Hewlett-Packard. One characteristic of these devices is that they use the Microsoft Windows CE (TM) operating system, which provides for pen input for selecting on-screen buttons, drop down windows, and electronic inking. However, a major design failing of these clam shell computers is that they topple over backwards if anything more than a very light pen touch is applied to the display screen. In practice this requires the user to grasp the computer manually to prevent it toppling backwards.

In addition, reference may be made to the eMate product from Apple Computer, Inc. This is a notebook sized computer with a pen sensitive display. In the eMate, the size of the screen is relatively small compared to the overall footprint. The screen is hinged at a fixed position: it does not slide backwards and forwards as, for example, the screen shown in Sony's US 4,960,256 does. However, the hinge position is not at the rear of the computer either, as in an ordinary clam shell. That is because the screen is relatively small and it is convenient to place the hinge just to the rear of the keyboard, which is about 2/3rds of the way towards the rear of the device, which has a built in carrying handle. Further, the base of the eMate is relatively heavy, so that the product does not readily tip backwards when the display is touched. That would be true even if the display were hinged at the back of the computer as in a conventional clam shell. Hence, although the eMate has many interesting features, the design problem of reconciling the need for a relatively large display (i.e. one that covers at least half of the actual footprint) with the goal of overall compactness is not addressed in this product. Nor is the tendency of a clam shell design to tip backwards under pen or touch input addressed.

Reference may also be made to US 5,267,123 to EO Europe Limited. This discloses a notebook format pen computer which, when closed, has the display upper-most. The display can be slid backwards to reveal a keyboard and can be inclined to a suitable viewing angle. Hence, it can operate as both a tablet (i.e. with the lid fully closed) and as a combination keyboard and pen driven device. The display screen has a rear support which gives the display some rigidity with respect to the base of the computer: i.e. it prevents the display from moving back towards a horizontal position under pen pressure even when the base remains stable. Prior art such as the EO Limited patent relate to full sized laptops dating form 1990 and the base and display used in such a device would have been heavy. Hence, no specific design features appear to have been included in order to minimise the torque associated with pen or touch input to the screen below a threshold level.

Reference may finally be made to EP-A- 96306974.5 to the present applicants. This application discloses a handheld computer with a touch and pen sensitive screen in which the screen and keyboard are mounted in such a way that, as the screen is opened up for use, the keyboard slides forwards, as does the base of the screen. Such a computer will be stable when the display is used for a wide range of pen and finger activated tasks, even where the pen or fmger touches an area near the top of the screen, where the torque it applies will be the greatest because the length of the moment arm about the turning axis is the longest. Hence, pen and finger activated menus that drop-down from the top of the screen and all other pen and finger activated features can confidently be used in such a computer. The embodiment disclosed in EP-A- 96306974.5 has been successfully commercialised as the Psion Series 5 and 5MX handheld computers. One feature of the design shown in EP-A- 96306974.5 however is that it is relatively expensive to manufacture.

Statement of the Present Invention

In accordance with the present invention, there is provided a computer with a touch sensitive and/or pen sensitive display, in which the position of the fully opened display is such that the torque typically applied by a finger or a pen to the top most pen or touch sensitive part of the display, in relation to a rotational axis about which the computer would rotate if it were to tip backwards, is less than that needed to cause the computer to tip backwards about that rotational axis, and including a keyboard fixed to a first portion of a base of the computer and further including a second, rear portion of the base that is caused automatically to move rearwards relative to the first portion of the base as the display is opened.

Once the rear portion of the base has automatically moved fully rearwards as the screen is opened up, the computer is rendered stable under normal pen or touch input. The approach of fixing the keyboard to the base and having the rear of the computer automatically extending rearwards as the screen is opened up results in a cheaper and more robust design than that contemplated in EP-A- 96306974.5.

Typically, the second, rear portion is a battery compartment which may move rearwards on tracks formed in the first portion of the base as the computer is opened. The tracks may be radiused so that the first portion of the base is raised to an angle to facilitate keyboard entry when the computer is fully opened. A computer in accordance with the present invention will not only be statically stable, but also stable when the display is used for a wide range of pen and finger activated tasks, even where the pen or finger touches an area near the top of the screen, where the torque it applies will be the greatest because the length of the moment arm about the turning axis is the longest. Hence, pen and finger activated menus that drop-down from the top of the screen and all other pen and finger activated features can confidently be used in a computer according to the present invention because the torques have been carefully determined to be insufficient to cause toppling.

This invention uses the design theory of deliberately minimising the torque associated with pen or touch input to the screen below a threshold level. Such a design feature only becomes desirable when without it you have a computer that would too readily topple backwards when its display is touched by a finger or pen. With the weight of components typically used in the current generation of mass market portable computers, a computer that is sub-notebook size or smaller will generally benefit from the present invention. However, the scope of the present invention should not be construed as limited to any size of computer.

The torque associated with typical pen or finger contact to the display can be reduced to below the amount that would cause toppling by sufficiently reducing the length of the moment arm, i.e. the length of the distance from the point of application of the turning force to the rotational axis about which the computer would rotate if it were to tip backwards. In the present invention, this approach is combined with a design in which opening of the lid/display automatically causes the rear section of the base to move apart from the front section of the base, on which a keyboard is mounted. When the display is in the fully open position, it is significantly displaced forwards from the position it would occupy if it were hinged at the rear of the computer in a conventional clam shell arrangement. This approach, as explained above, reduces the length of the moment arm.

Brief Description of the Drawings

An example of a portable, palmtop computer according to the invention will now be described with reference to the accompanying drawings, in which :-

Figure 1 is a perspective view from above showing the computer in a closed position;

Figure 2 is a perspective view from above showing the computer in a partly open position;

Figure 3 is a perspective view from above showing the computer in a fully open position;

Figure 4 is a side view showing the computer in a closed position;

Figure 5 is a side view showing the computer in a partly open position; and

Figure 6 is a side view showing the computer in a fully open position.

Figure 7 is a side sectional view showing the computer in a fully open position resting on a docking station. Detailed Description

Referring now to the drawings, Figures 1 , 2 and 3 show a handheld computer in respectively the closed, partly open and fully open positions. The computer comprises a front base 1 , a lid 2 and a rear section 3. The battery compartment is within rear section 3. As the user opens the lid 2 to reveal a display 5 and keyboard 6, the lid 2 moves in a manner constrained by three hinges: first, hinges 10A and 10B connect the lid 2 to the top face 3 A of the rear 3. As lid 2 is opened up, it rotates about hinges 10A and 10B. Secondly, each side of the lid 2 includes a channel 12; a small fixed peg extends from each of the upper sides 7 A of the rear 3 into each channel 12. As lid 2 opens up, the channel 12 moves up relative to each peg (not shown), with the pegs acting as pivots. Thirdly, the lid 2 is hinged to the rear of the keyboard at hinges 4 A and 4B. As the lid is opened up, the combination of the three hinge renders the initial force needed to open the lid very slight: this is a significant improvement over conventional clam shell designs, in which the initial force needed to open up a claim shell can be relatively high, sometimes requiring a biasing spring for assistance. Equally, closure of the lid requires that a relatively light force be applied to the rear section 3; hence, a user can grasp the open unit in one hand and easily close it using one hand.

As the lid is progressively opened up further, the front base 1 moves forward relative to rear section 3 on radiused tracks 8 engaging pegs within the lower sides 7B of the rear section 3 (or equivalently, the rear section moves rearwards relative to the front section). The upper and lower sides 7 A and 7B of the rear section 3 pivot about a rear hinge 13, opening up as the lid opens in a manner defined by the hinges 10A and 10B and the pegs extending from upper sides 7 A into channels 12. These trace an arc movement, causing the upper and lower sections 7A and 7B, as lid 2 is opened, to separate and then move together again. Hence, in both the fully open and fully closed lid positions, the upper and lower sections 7A and 7B are fully closed, but they can be seen to have separated in the mid-way position, shown in Figure 2 and Figure 5. In the fully open position, the torque associated with pen (not shown) or fmger (not shown) contact on the display 5 has been reduced to below the amount that would cause toppling by sufficiently reducing the length of the maximum moment arm, i.e. the length of the distance from the point of application of the turning force to the top of the touch or pen sensitive part of the display to the rotational axis about which the computer would rotate if it were to tip backwards. This has been achieved by using the hinge mechanism described above that causes the display 5, when fully opened, to be displaced forward from, but substantially parallel to, the approximate, ordinary viewing position it would be in if the display were hinged at a fixed point at the rear of the display as in a conventional clam shell design. This displacement reduces the length of the moment arm. In this embodiment, the pen/finger activation force of the display has been set to 20g or 0.2N. The force need to tip the computer backwards is however approximately 50g or 0.5N.

The lid 2 can, when fully open, rest upon the top face 3 A of the rear section 3: this gives rigidity to the screen 5 and the base 6 in that tapping the touch screen 5 with a pen or finger will not cause the lid 2 to rotate backwards about its hinges, unlike a conventional clam shell design.

(This effect is different from preventing the computer from toppling backwards: with a conventional clam shell notebook computer with a heavy base, it is usually possible to cause the display to pivot about its hinge to the base by pushing firmly enough with a finger.

That occurs when the torque associated with finger pressure is greater than the resistance to the rotational movement of the display associated with the friction of the hinge.) Hence, by shifting the display forward, the current embodiment removes the need to have a complex friction mounting for the lid 2 or other form of support; instead, the lid 2 rests firmly against the rear of the base 3 when fully opened, at a viewing angle of 146 degrees, as shown on

Figure 6. In this embodiment, a line drawn from the start position of the base of the display when closed to the resting position of the base of the display when fully open will not be horizontal: as shown in Figure 6, the keyboard when open makes an angle of about 12 degrees with the horizontal. This is to ensure that, when opened, keyboard 6 presents at the right angle to the user for typing.

The illustrated embodiment is designed to rest on a docking station 20, shown in Figure 7. The side sectional view of the computer usefully also shows the hinges 10A/10B which connect the lid 2 with the top of the base section 3 A. The hinge 13 connecting the upper and lower rear base sections 7A and 7B are also apparent.

The precise amount of the necessary displacement has been determined by constructing numerous models to test various set-ups.

Further, although the current and foreseeable designs of non-tablet computers will employ a keyboard, it is conceivable that the ergonomic advantages offered by the present invention will render its basic approach suitable for a device in which there is no keyboard at all. Hence, the term 'keyboard' used in this specification should be construed to cover not merely a conventional keyboard, but also any kind of surface, which may or may not provide interaction with the computer. For example, embraced within the invention would be a computer in which the 'keyboard' was simply a plain support on which a user might rest a part of her hand whilst writing on the display with a pen.

Claims

1. A computer with a touch sensitive and/or pen sensitive display, in which the position of the fully opened display is such that the torque typically applied by a finger or a pen to the top most pen or touch sensitive part of the display, in relation to a rotational axis about which the computer would rotate if it were to tip backwards, is less than that needed to cause the computer to tip backwards about that rotational axis, and including a keyboard fixed to a first portion of a base of the computer and further including a second, rear portion of the base that is caused to move automatically rearwards relative to the first portion of the base as the display is opened.

2. The computer as claimed in Claim 1 in which the second, rear portion moves rearwards on tracks formed in the first portion of the base as the computer is opened.

3. The computer as claimed in Claim 3 in which the tracks are radiused so that the first portion of the base is raised to an angle to facilitate keyboard entry when the computer is fully opened

4. The computer as claimed in Claim 1 in which the second, rear portion is a battery compartment.

5. The computer as claimed in Claim 2 in which the display is mounted in a lid and the lid is itself hinged on three hinging mechanisms, the first being a hinge with the top of the rear portion of the base, the second being a pivot with each of two sides of the rear portion of the base, and the third being a hinge with the rear of the keyboard.