A graphics tablet (also digitizer, digitizer pen tablet ) is a pointing device for computer inputs. The tip of a special show tool, usually a pen or stylus called a puck with crosshair is moved on the tablet. From her go from impulses over which the tray receives the information about the pen pressure and additional keys pressed at the respective position. In advanced models, more information, such as pen tilt, rotation pin, finger pressure or several tools can be detected.
- 2.1 Accuracy and handling
- 2.2 Pressure sensitivity
- 2.3 Absolute Positioning
The pin includes a coil that generates a directed electromagnetic field. Conductor loops in the tray be determined by comparison of the induced signal strengths, the pointer position. Additional information such as pen pen pressure or pressing a button on the pen are digitized, modulated the electromagnetic field and sent together with the position data to the computer.
The pins are powered by either a built- in battery pin ( pin active ) or by induction (passive pen) from the tray. In resistive screens, however, the screen surface is pressure sensitive, such that an operation by touch such as the hand or other objects is possible; this is also the case only in some new graphics tablets.
Alternatively, the pin can also be a so-called puck to be used, which is moved as a computer mouse on the tablet with the aid of a reticle allows more precise aiming of the tablet and therefore the digitization of templates. Here, the coil is usually placed visible to the crosshairs around. Some manufacturers offer a variety of pen nibs for a shape adapted to the simulated tool haptic perception, to tools that are modeled after an airbrush.
If different tools available, so an identification signal of the tool is often automatically transferred to the tablet, which saves switching the tool by hand and enables individual settings for each pen, just as in classical drawing tools.
Most graphics tablets also have keypads next to the contact -sensitive surface, partly virtual keypads on the edge of the area to have quick access to program functions or to change settings of the current tool.
Accuracy and handling
Controlling the cursor by a pin brings several advantages:
- The control of brushes and similar tools in graphics applications is with a tablet much more precisely than with the mouse.
- Where forms can be indicated with a mouse only, you really can paint all the pictures and draw accurately. The pin is out of the sensitive built muscles of the fingers and explicitly the index finger while the mouse by the whole hand is passed over the elbow and the wrist bone.
- Since the signal of the pin to penetrate the paper, it is possible durchzupausen paper present drawings in the computer.
- Some graphics tablets also allow the detection of the angle at which the pen is to the tablet.
- Program functions can be special keys on the tablet surface dismissed.
- The operation is intuitive; it possible for individuals who are not familiar with using a mouse (but write ) deal with a stylus.
Graphics Tablets or their pins can evaluate the pressure intensity to control, for example, in a graphics software brush size or opacity ( see picture).
Unlike the PC mouse that recognizes only relative movements, there is the absolute coordinates of a graphics tablet with about each point on the tablet corresponding to a point on the screen. In the mouse, however the mouse pointer is in each case " pushed " from its current position.
Example: If you want to select a point on the screen, you have to first push the mouse there. In a graphics tablet, however, "pushes" you directly to the appropriate place, so that the cursor is placed immediately there. In addition, graphics tablets are needed in professional applications for the precise tracking of lines of paper documents to digitize drawings such as plans - such work is not possible at all with the mouse.
- Those who, like tablet will work with both the keyboard has only the pin drop before he types with both hands. The re receiving and positioning the pen is more complex than the handle for the mouse, in which the repositioning is not necessary.
- Great graphics tablets require a lot of desk space, while smaller models, the usable range is limited.
- In conjunction with a high-resolution monitor no small tray should be used because precise positioning by the difference in size (more pixels on one area of the tablet ) tired trying very hard and fast.
- Programs that affect the behavior of the mouse do not function properly. Thus, the position of the cursor is changed as in some games. Since this is not possible with a tray, there is a failure of the program, for example, if the unchanged position of the cursor is processed as a new movement.
- Are always the same menu items chosen or actions performed, the surface of the tablet scratched stronger at certain points. This, in turn, the pin wears out stronger, and it suffers from sensitivity.
Graphics tablets have partially activities (eg painting, drawing on the PC, etc.) and are made possible only in the following areas have become a major tool:
- Digital Imaging and Digital Painting: Modes (tools) can be chosen much faster and corrections are made more precise. The exposure can be improved and precisely dosed.
- Design (graphic, industrial, Textile and Fashion Design): Quick sketches for illustrating ideas are partially made only digital. The advantage is in the fast exchange of digital designs ( over paper sketches no scanning required). The same applies to illustrations. Modern CAD software offers some already special program internal functions for the new way of working - the implementation of sketch to finished object is faster and more intuitive.
- Audio and video editing (film and television): Matte Paintings ( digitally painted film sets ) have long been an integral part of films and are now made almost exclusively in digital form. The advantages are flexible in working with layers and no elaborate scans.
- Presentation: In a presentation on a projector are quickly inserted using a graphics tablet or comments, just as lectures, pre- calculates mathematical calculations quickly and simultaneously stored digitally.
- Online tutoring in virtual classrooms: Newer forms of tutoring lessons - in particular when learning support is outsourced (see offshore tutoring ), require working with a graphics tablet and the visualization of what is written on a " shared whiteboard ". This happens mostly in a virtual classroom (or virtual conference room ). This combination of "Application Sharing" and the tablet replace pen and paper. Online tutoring in the form of "Live E -learning " is used mainly in the English language is increasingly gaining acceptance. In the German -speaking world this new form of tutoring instruction is relatively little spread.
- 3D computer graphics: In this area make programs like ZBrush or Mudbox to create detailed models much easier. In these types of programs you paint and influenced by the geometry of tools whose effects are particularly dependent on the amount of pressure.
- One that has now become unusual application is the use of a graphic tablet as a user interface for a CAD program. Here, only a small portion of the tablet was used as an input surface for the screen, while around this area around the buttons to operate the program were arranged. The trays used for this purpose typically had a working area of 12 "x 12" ( 305mm x 305mm round ) or 12 "x 18" ( 305mm x 457mm approx ). The user interface was applied in the form of a print on a paper or plastic sheet, which was placed under the transparent cover of the tablet. Corresponding requirements for popular programs such as AutoCAD are included with the tablet, as were with the software packages tablet editions. For this also the associated drawing files have been provided so that you could adjust and print the user interface to your needs with the software. Virtue of its role as a replacement for the mouse, these trays usually did not have a recognition of the print pressure. An input device were pucks with 4 or 16 keys, as well as pins with two or three buttons on the application. Major manufacturers of these tablets were for example Summa Graphics / Calcomp, Acecad or genius (not to be confused with the CAD software manufacturer). After from about the mid-1990s in CAD programs originally menu-based user interface has been changed to graphical user interfaces are today Grafiktabletts that once constituted an almost essential accessory of a powerful CAD workstation, used in everyday life as well as not for this purpose. In modern 3D CAD systems is now often used in addition to the mouse as an input device, a 3D mouse for convenient navigation.
Basically you can use any kind of software with a graphics tablet with a graphical user interface that can also be operated with a mouse, but the following applications, for example, to use the technical possibilities accordingly:
- ZBrush, Mudbox
- Maya, Softimage XSI, Blender
For tablet PCs corresponding variants were developed by Microsoft - Windows operating systems, which are optimized for a keyboard less working with the pen. It has built-in handwriting recognition, the biomechanical properties such as writing pressure and pen inclination evaluates (if any), generally the operating systems have been adapted by various features on the operation without the usual keyboard. Software that is adapted to operate with a pin, it is also from other manufacturers (see, tablet PC).
For Apple Macintosh Inkwell handwriting recognition has been integrated into the operating system Mac OS X.