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Early tablet computers

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A Tablet PC is a notebook- or slate-shaped mobile computer. Its touchscreen or digitizing tablet technology allows the user to operate the computer with a stylus or digital pen, or a fingertip, instead of a keyboard or mouse.

The form factor offers a more mobile way to interact with a computer. Tablet PCs are often used where normal notebooks are impractical or unwieldy, or do not provide the needed functionality.

Technology

The Tablet PC is a culmination of advances in shrinking notebook hardware and improvements in integrated digitizers as methods of input. A digitizer is typically integrated with the screen, and correlates physical touch or digital pen interaction on the screen with the virtual information portrayed on it. A tablet's digitizer is an absolute pointing device rather than a relative pointing device like a mouse or touchpad. A target can be virtually interacted with directly at the point it appears on the screen.

Older Tablet PCs had little if any persistent memory - instead they could be passed between users that could tick off or sign on a document that is displayed.

Inputting data

A user can enter text using handwriting recognition, an on-screen (virtual) keyboard, speech recognition, or standard keyboard. Shorthand-like entry methods, which enable pen-driven input at speeds comparable to touch-typing, and are unique to the Tablet PC, include AlphaTap, Inscribe, Shark (a.k.a. ShapeWriter) and MessagEase.

Tablet PCs using Windows XP Tablet PC Edition or Windows Vista may utilize the Ink object as a means of data input and storage. This is a data type first created as part of the Windows XP Tablet PC Edition API that allows one to manipulate and process handwritten data, including recognition results and, in some cases, the pressure information for each part of the stroke. Properties of Ink can be changed in much the same way as properties of other objects, and the data can be saved to allow future reference. Many applications referencing the Ink object also allow handwritten notes to be filtered and searched through, based on the recognition results stored when Ink is saved.

A popular use of the Tablet PC form factor is to enable computerized manipulation, organization, and reading of large amounts of printed information. In particular, casual readers may download electronic versions of their favorite books to read on their Tablet PCs, or students may scan in the pages of textbooks and just bring their Tablet PCs to class in lieu of bulky textbooks. Universities have begun integrating Tablet PCs with shared resources such as whiteboards, where students and teachers can interactively manipulate the same images.

Handwriting recognition

Modern day processors and advances in recognition algorithms make the conversion from handwriting to text far more practical now than it was in early attempts of Tablet PCs.

Current handwriting recognition technology employed by Tablet PCs are effective at recognition of natural cursive writing, rather than letter-by-letter recognition. Letters in the context of words are recognized for finding possible sequences within an input block of handwriting. The sequences are then compared to a dictionary of words for determining the most likely sequence, with a list of alternatives presented to the user. On known (in-dictionary) words, this method is more accurate than letter recognition, however modern system also address recognition of out-of-dictionary words, notably email and web addresses, new slang terms, proper names, and domain-specific terminology. Handwriting recognition software often presents a letter recognizer option to better enable precise input.

Handwriting recognition in Windows

The integrated handwriting recognition in Windows XP Tablet PC Edition 2005 can recognize print, cursive, or mixed writing. Accuracy can be increased by configuring the recognizer to expect left-handed writing or right-handed writing. Recognition in a variety of languages is available with the install of a recognizer pack. The handwriting engine cannot be trained in Windows XP, forcing the user to retrain their handwriting to be better recognized by the system.

The integrated handwriting recognition in Windows Vista is, however, trainable in a variety of ways. Vista offers the option for users to correct specific errors in recognition, provide samples for a set of common characters, or to provide a large set of handwriting samples directly on the computer. There is also the option to use automatic learning - this feature pays attention to things like which words the user includes in emails, and which recognition results they correct. It automatically adds those words to the dictionary and/or increases the likelihood of those words being recognized for improved recognition in the future.

File:TabletPC 2004.jpg
A Typical Tablet PC Screenshot, showing a docked TIP from Tablet PC Edition 2005

Tablet PC Input Panel

The original Tablet PC Input Panel (TIP) included a handwriting panel, an on-screen keyboard, and a write anywhere function which allowed the user to literally write anywhere on the screen, after which the recognized data would then be sent to the currently focused input box.

The enhanced TIP introduced in the Service Pack 2 update (Windows XP Tablet PC Edition 2005) includes improved handwriting recognition, the option to correct a recognition error before it is sent to an application, and integrates the option to manually add a word to the computer's dictionary to improve its recognition in the future. The TIP can also add inline correction functionality to applications that support Advanced Text Input Services. This works by the TIP temporarily storing the recognition results from data that it inputs into the application. This version of the TIP removed the write anywhere function in favor of a floating interface. In applications which used certain supported text controls, an icon would appear when the pen was in proximity to the screen. Tapping or hovering over this icon would open the floating TIP, which would expand horizontally and vertically as needed when the user wrote to the edge of the window. For applications which could not pop up the floating TIP, the docked state was still supported, in which the TIP would stick to the top or bottom of the screen, moving all other windows out of the way (expanding downward if docked at the top).

Types of digitizers

Active digitizer

An active digitizer, used in most tablet PCs, can track the position of the pen when it is in proximity to the digitizer. This feature allows the user to "hover" over items on the screen. This can provide helpful functionality such as the ability to view tooltips and auto-hidden items, and to navigate through menus without accidentally activating an item.

Active digitizers can be installed behind the screen, allowing for maximum visibility, although most manufacturers install protectors over the screen to decrease the risk of damage to the LCD.

By using an active digitizer, the user's hand may rest on the screen without affecting the image or mouse pointer; only movement of the stylus affects the mouse pointer.

The most widely used digitizer, a Wacom digitizer projects electromagnetic signals that are reflected by the tablet's pen. The computer then calculates the position of the stylus based on the point in the electromagnetic field the stylus interacts with. Electronic switches inside the pen can change paccurate sense of the pen's position. This can make some tasks difficult, e.g. slowly drawing straight lines, aiming at interface elements at the edges, or writing small characters.

UC Logic and Finepoint make other digitizers used in a few tablet PCs. Models incorporating these digitizers suffer from the lack of support in many graphics applications.

Averatec's C3500 line uses UC Logic digitizers. Compaq's TC1000 and Gateway's Convertible Notebook series use Finepoint digitizers.

Finepoint's digitizer technology incorporates a battery-powered pen which actively transmits RF signals to be received by the tablet sensor. This results in lower power usage of the tablet PC itself, but greater size and weight of the pen because of the battery. The main advantage is that the accuracy problems related to interference from metal at the edge of the screen is not an issue.

Early revisions of Finepoint's digitizer, used in Compaq's TC1000, specifically suffered from the use of obscure, non-rechargeable AAAA batteries to power the pen, and did not support pressure sensitivity.

Modern Gateway Convertible Notebooks (CX200/210, CX2600/2700, etc.) use Finepoint MP-800 digitizers. The batteries inside these pens are recharged by an inductance coil while the pen is stored in its compartment. Concerns over the reliability of the pen are the main problem with these models.[1]

Passive digitizer

A passive digitizer, used in a touchscreen based tablet PC, only knows where the position of the finger is when the user presses down on it. This causes the pointer on the screen to jump to the location of the press and instantly "click". Passive digitizers are either capacitive or resistive.

The capacitive touch screen panel is coated with a material that stores electrical charges. When the panel is touched, a small amount of charge is drawn from the point of contact (the finger). Circuits located at each corner of the panel measure the charge and send the information to the controller for processing. Capacitive touch screen panels must be touched with an unprotected finger, unlike resistive, that can be operated by gloved hands or stylus.

The resistive touchscreen panel is coated with a thin metallic electrically conductive and resistive layer that causes change in the electrical current which is registered as a touch event and sent to the controller for processing. The resistive touchscreen panel can be operated by fingertip, stylus or gloved hand and does not need direct skin contact in order to operate.

Both capacitive and resistive touchscreens offer lower accuracy and a higher rate of error—e.g. when the user's hand rests on the screen surface—which makes them less common in tablet PCs.

Hybrid digitizer

Windows Vista adds formal support for hybrid digitizers including the ability of applications to distinguish between pen and touch input, as well as ability to turn touch input on or off. [2]

More recently, tablet PCs have been equipped with hybrid digitizers that respond to both active pen and passive touch input. This allows the user to utilize simple finger based navigation, as well as the precision of pen input. An example of a tablet PC equipped with a hybrid digitizer is the Lenovo X60 Tablet with MultiTouch and the LG C1

In June 2007, TabletKiosk began shipping the Sahara Slate PC i440D, a Slate PC with a hybrid display (although current Vista drivers only allow the active digitizer at this time...XP Tablet 2005 supports full hybrid function)

Stroking pen

The stroking pen is a combination of a regular biro and a digitizer. While writing on a piece of paper that roughly fits onto the graphics tablet (or tablet PC) an exact digital copy is produced (as long as the paper stays in position). The advantages of this device are: a more natural writing experience, longer battery life of the tablet PC (because the display brightness can be turned down without limiting the visibility) and a spare (exact) paper copy for moments when it is needed (e.g., exams or loss of data on the tablet).

Forms

Slates

Slates, which resemble writing slates, are tablet PCs without a dedicated keyboard. Keyboards can usually be attached via a wireless or USB connection.

These tablet PCs typically incorporate small (8.4-14.1 inches/21–36 cm) LCD screens and have been popular for quite some time in vertical markets such as health care, education, and field work.

Slate models are often designed with a focus on pure mobility, that is, the less to carry, the better.

Rugged tablet PC models are usually in the slate form factor, because without a keyboard, there are fewer moving parts to break.

Thin-client slates

Thin-client slates consist of a touchscreen and an integrated wireless connection device. These units by design have limited processing power which is chiefly involved with Input/Output data processing such as video display, network communications, audio encoding/decoding, and input capture (touchscreen input, bar code reading, magnetic stripe reading (credit card swipe). The unit transmits data via a secured wireless connection to a remote server for processing.

Thin-client slates have the design advantages of a very lightweight form factor, more secure data (no data storage on the slate computer), long battery life (no processor to power). The Panasonic Toughbook 08 is representative of the application of thin-client computing to tablet PCs.

Convertibles

Convertible notebooks have a base body with an attached keyboard. They more closely resemble modern notebooks/laptops, and are usually heavier and larger than slates.

Typically, the base attaches to the display at a single joint called a swivel hinge or rotating hinge. The joint allows the screen to rotate around 180° and fold down on top of the keyboard to provide a flat writing surface. This design, although the most common, is a point of weakness on a convertible.

It is feasible for manufacturers to overcome these weak points. A convertible design, the Panasonic Toughbook 19 is a fully ruggedized convertible.

One model by Acer has a sliding design in which the screen slides up from the slate-like position and locks into place to provide the laptop mode.

Convertibles are by far the most popular form factor of tablet PCs, because for people who are unsure about the practicality of using the pen as the primary method of input, the convertibles still offer the keyboard and pointing device of traditional notebooks as a backup plan.

HP Compaq tablet PC with rotating keyboard

Hybrids

Hybrids, coined by users of the HP/Compaq TC1000 and TC1100 series (depicted to the right), share the features of the slate and convertible by using a detachable keyboard which operates in a similar fashion to a convertible when attached.

This is not to be confused with slate models that have a detachable keyboard—detachable keyboards for pure slate models do not rotate around to allow the tablet to rest on it like a convertible.

Despite a loyal following of users, the hybrid form factor has not received any recent updates after the TC1100 was discontinued.

History

  • Late 1960s
    • Alan Kay of Xerox PARC proposed a notebook using pen input called Dynabook.
  • 1989
    • The first commercially available tablet-type computer was the GRiDPad from GRiD Systems, released in September. Its operating system was based on MS-DOS.
  • 1991
    • The Momenta Pentop was released.
    • GO Corp announced a dedicated operating system, called PenPoint OS.
    • NCR released model 3125 pen computer running MS-DOS, Penpoint or Pen Windows.[3]
    • The Apple Newton entered development; although it ultimately became a PDA, its original concept (which called for a larger screen and greater sketching capabilities) resembled that of a tablet PC.
  • 1992
    • GO Corp shipped PenPoint and IBM announced IBM 2125 pen computer (the first IBM model named "ThinkPad") in April.[4].
  • 1993
    • The first commercialized tablet computer systems available to the consumer market were the IBM ThinkPad 750P and 360P introduced in 1993[5]
    • AT&T introduced the EO Personal Communicator combining PenPoint with wireless communications.
  • 1999
  • 2000
  • 2002
  • 2002-Present
    • Recent advances in computer technology and lowering of manufacturing costs allowed for tablet PCs to become more affordable and widespread.
  • Present
    • Windows Vista has been released to the public. Many of the different editions include Tablet PC support. The tablets are even more affordable and it is possible to get a decent tablet from about US$1500 and up.

System software

Microsoft

The operating system on which most tablet PCs run is Windows XP Tablet PC Edition. Tablet PC Edition is a superset of Windows XP Professional, the difference being tablet functionality, including alternate text input (Tablet PC Input Panel) and basic drivers for support of tablet PC specific hardware. Requirements to install Tablet PC Edition include a tablet digitizer or touchscreen device, and hardware control buttons including a Ctrl-Alt-Delete shortcut button, scrolling buttons, and at least one user-configurable application button.

Service Pack 2 for Windows XP includes Tablet PC Edition 2005 and is a free upgrade. This version brought improved handwriting recognition and improved the Input Panel, allowing it to be used in almost every application. The Input Panel was also revised to extend speech recognition services (input and correction) to other applications.

With Windows Vista, the Tablet PC functionality no longer requires a separate edition. Tablet PC support is built into all editions of Windows Vista with the exception of Home Basic. This extends the handwriting recognition, ink collection, and additional input methods to any computer running Vista even if the input device is an external digitizer, a touch screen, or even a regular mouse.

Windows applications

There are various operating systems in use on devices marketed as tablets. Note that most tablet PC software is targeted particularly for the Microsoft Tablet PC API, and will not run on devices without Windows XP Tablet PC Edition. Care should be taken when researching a tablet system or any device or software that claims to be designed for tablet PCs, as the phrase does not guarantee compatibility.

Applications developed for the tablet PC cater to the form factor and functionality available on the platform. Many forms of applications incorporate a pen-friendly user interface and/or the ability to handwrite directly in the document or interface.


Microsoft has released free software specifically for use on tablet PCs. Notable releases are the Experience Pack for Tablet PC and the Education Pack for Tablet PC. Between these two major releases, a number of applications and add-ons are installed that make use of the form factor and features of the tablet PC. A brief description of the applications included follows:

Experience Pack

[7]

  • Ink Desktop: an Active Desktop control designed to run in the background and allow the user to write directly on the desktop.
  • Snipping Tool: a screen capture application which allows the tablet pen to be used to select a portion of the screen and then annotate it and save as a file or send in an email.
  • Ink Art: a painting application developed by Ambient Design originally as ArtRage, licensed to Microsoft for release to Tablet PC users.
  • Ink Crossword: a crossword application developed to mirror the experience of a paper crossword puzzle on a tablet PC.
  • Media Transfer: a synchronization utility designed to download music, pictures, and videos off of computers in the same network.

Education Pack

  • Ink Flash Cards: an application designed to assist memorization by using a flash card approach, enabling the user to handwrite their own flash cards and display them back in a slideshow.
  • Equation Writer: a recognition tool specializing in converting handwritten mathematical equations to a computer-generated image for pasting into other documents.
  • GoBinder Lite: an organization and note-taking application developed by Agilix Labs.
  • Hexic Deluxe: a game with a tablet PC specific gesture enabled for easier use with the tablet

Linux

Running Linux on tablet PCs is as practical as on conventional notebooks. More recently, tablet PCs may also be configured with Linux pre-installed. One early implementation of a Linux tablet was the ProGear by FrontPath. The ProGear used a Transmeta chip and a resistive digitizer. The ProGear initially came with a version of Slackware Linux, but could later be bought with Windows 98. Because these computers are general purpose IBM PC compatible machines, they can run many different operating systems. Xorg now supports screen rotation and tablet input through Wacom drivers, and handwriting recognition software from both the QT Qtopia and GTK+ Maemo projects provide promising free and open source systems for future development. However, little mature desktop-oriented software of the sort has arisen, leading many users to rely on on-screen keyboards and alternative text input methods like Dasher.

Apple

The aftermarketer Axiotron has introduced aftermarket, heavily modified Apple MacBooks called ModBooks, a Mac OS X-based tablet PC. It uses Apple's Inkwell for handwriting and gesture recognition and bundles additional digitization software from Wacom. The product is not yet available and has been delayed indefinitely.

Tablet PC distinction

[original research?]

There is dispute on the distinction between "tablet PC" and "Tablet PC". One issue with the distinction is that there was never a standard definition of what constitutes as a tablet PC.

The phrase "Tablet PC", with the specific capitalization of the T, is generally regarded as the platform as introduced by Microsoft and its partners in 2002: a complete computer, capable of running applications under its own power, with an integrated digitizer, hardware function buttons, and the Windows XP Tablet PC Edition operating system.

Some mobile PCs utilizing other operating systems include a digitizer for user input and can still be regarded as a tablet PC in that it is capable of providing the same functionality.

Wireless displays with integrated digitizers are sometimes marketed as tablets, but are more akin to thin clients in that they do not perform any functionality themselves, but act as a terminal to a single computer. Such devices may be more accurately referred to as a "drawing tablet" rather than the less descriptive word "tablet," as the digitizer functionality of these displays is usually used as a drawing device. These devices, as well as internet appliances with a slate-like design, are not necessarily fully functional devices as the tablet PC. Thin clients with a slate-like design may be used in vertical markets such as point of sale and assembly line.

Tablets vs. traditional notebooks

The advantages and disadvantages of tablet PCs are highly subjective measures. What appeals to one user may be exactly what disappoints another. The following are commonly cited opinions of the tablet PC platform:

Advantages

  • More natural form of input — sketching and handwriting are a much more familiar form of input than a keyboard and mouse, especially for people who are new to computers.
  • Gesture recognition — gestures (moving the stylus in special patterns over the screen) are powerful ways to increase efficiency. Many applications, or the operating system itself, can be programmed to respond in different ways to certain gestures created by the pen.
  • Note-taking — taking handwritten notes and drawing diagrams at a class or conference increases productivity and retention of information. The notes can also be searched automatically if handwriting recognition is implemented.
  • Accessibility — those who are physically unable to type can utilize the additional features of a tablet PC to be able to interact with the electronic world.
  • Digital art — tablets are often necessary for professional digital artist work. For many, mouse movement is too jerky to be used as a precision tool.
  • Portability — slate tablets and hybrids without keyboards are very slim and light compared to typical laptops and can easily be tucked under the arm like a book.
  • Horizontal orientation — most tablet PCs do not interrupt line of sight since they lie flat on the table or in one's arms. This allows for better interaction in business meetings and conferences and also makes it easy for digital artists who wish to draw on a horizontal medium.

Disadvantages

  • Higher cost — convertible tablet PCs cost roughly $300 more than their non-tablet counterparts as of 2005. This premium is expected to fall to as low as $75 by 2007.[8] However, some models are intentionally priced at the same point or lower than equivalent notebooks without tablet functionality.
  • Screen size — the size of tablet PC screens currently peaks at 14.1 inches. However, some models make up for this with very high resolution (a higher pixel density per unit area).
  • Input speed — maximum handwriting speed can be significantly slower than maximum typing speed, which can be as high as 50-150 WPM.
  • Screen damage risk - Because Tablet PC's are handled more than conventional laptops yet built on the frames of conventional notebooks, and because their screens also serve as input devices, many Tablet PC's run a higher risk of screen damage. PDAs carry some of the same risk.
  • No built in optical drive (some Tablet PCs) — due to need for low mass

Designing around disadvantages

Manufacturers can design additional durability into the displays of tablets to effectively reduce screen damage risk, hinge failure, and screen size limitations. As an example, Panasonic Computer Solutions Company designed the Toughbook 19 specifically to overcome the screen damage issue potential. The use of scissor shock absorbers mounted to the screen, flexible connectors for data cables, molded magnesium alloy screen casing, durable and replaceable screen overlayments, and purpose built convertible hinges impact reliability. However, handheld models of computer such as the OQO Model 2 have a retractable keyboard that slides out sideways as a measure against having weak hinges and that the clamps for the sideway retracting keyboard are stronger if you put it into proportion to the robustness of the shell.

Major tablet PC Manufacturers include Acer, Asus, Fujitsu, Gateway, Inc., Hewlett-Packard, IBM, Lenovo Group, LG Electronics, MobileDemand,Motion Computing, TabletKiosk, NEC, Nokia (e.g. 770 and N800), Panasonic, Sony-Ericsson and Toshiba.

Popular models include:

Slate

  • PaceBlade P120
  • Fujitsu Stylistic ST5010
  • Electrovaya Scribbler SC2000, SC3000, SC3100
  • MobileDemand xTablet T8600 Rugged Tablet PC
  • Motion M1200, M1300, M1400, LE-Series, C5, LS800, LE 1700 and C5 which is targeted towards the healthcare industry
  • NEC Versa LitePad
  • Panasonic Toughbook 08
  • TabletKiosk Sahara i400 series
  • Samsung Q1
  • Nokia 770 and N800
  • SonyEricsson P990

Convertible

  • Acer TravelMate C100/C300/C310
  • Asus R1F
  • Averatec C3500 Series
  • Fujitsu LifeBook P1610(Slim, Ultra-portable, Small)/T4020, /T4210, /T4220 (Latest)
  • Gateway CX210/M285/S7200
  • HP Compaq TC4200/TC4400
  • HP TX1000/TX1020/TX1210us
  • Lenovo ThinkPad X41
  • Lenovo ThinkPad X60 Tablet (known popularly as "X60t")
  • Lenovo ThinkPad X61 Tablet
  • LG XNote C1
  • LG LT-20-47CE
  • Panasonic Toughbook 19
  • Toshiba Portegé 3500/M200/M400/M405/R400
  • Toshiba Satellite R10/R15/R20/R25
  • Toshiba Tecra M4/M7

Hybrid

See also (programs)

References

  1. ^ http://www.newsfactor.com/story.xhtml?story_id=001000000XOI
  2. ^ http://msdn2.microsoft.com/en-us/library/ms699430.aspx
  3. ^ NCR announces pen-based computer press release, retrieved 2007-04-20
  4. ^ Penpoint OS shipping press release, retrieved 2007-04-20
  5. ^ http://www.pc.ibm.com/us/thinkpad/anniversary/history.html
  6. ^ http://www.microsoft.com/windowsxp/tabletpc/default.mspx
  7. ^ http://www.microsoft.com/windowsxp/downloads/tabletpc/experiencepack/overview.mspx
  8. ^ http://news.com.com/Convertibles+The+new+laptop+bling/2100-1044_3-5900655.html

Information

Tablet PCs in education

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