State and immediate prospects for the development of the computer market. Digitizers. Digitizers and their design

Digitizer

A digitizer, or tablet, as it is also called, consists of two main elements: a base and a cursor that moves across its surface. This device was originally intended for digitizing images. When you press the cursor button, its location on the tablet surface is fixed, and the coordinates are transferred to the computer.

Digitizer is often associated with managing commands in AutoCAD and similar systems using overlay menus. Menu commands are located in different places on the surface of the digitizer. When the cursor selects one of them, a special software driver interprets the coordinates of the specified location, sending the corresponding command for execution.

The use of a tablet in creating drawings and sketches on a computer plays an important role. The artist draws on the screen, but his hand moves the pen across the tablet. Finally, the digitizer can be used simply as an analogue of a mouse. A special case is pressure-sensitive digitizers.

Operating principle

The operating principle of the digitizer is based on fixing the cursor location using a grid built into the tablet, consisting of wire or printed conductors with a fairly large distance between them (from 3 to 6 mm). But the mechanism for registering the cursor position makes it possible to obtain an information reading step much smaller than the grid step (up to 100 lines per mm). The step of reading the information is called digitizer resolution.

Based on manufacturing technology, digitizers are divided into two types: electrostatic (ES) and electromagnetic (EM). In the first case, a local change in the electrical potential of the grid under the cursor is recorded. In the second, the cursor emits electromagnetic waves, and the grid serves as a receiver. Wacom has created technology based on electromagnetic resonance, when the grid emits and the cursor reflects a signal. But in both cases the receiver is the grid. It should be noted that when operating EM tablets, interference from emitting devices, in particular monitors, is possible.

Regardless of the registration principle, there is an error in determining the cursor coordinates, called digitizer accuracy. This value depends on the type of digitizer and the design of its components. It is affected by the imperfection of the tablet’s recording grid, the ability to reproduce the coordinates of a stationary cursor (repeatability), resistance to different temperature conditions (stability), cursor quality, noise immunity and other factors. The accuracy of existing tablets ranges from 0.005 to 0.03 inches. On average, the accuracy of electromagnetic digitizers is higher than that of electrostatic digitizers.

The acquisition grid readout step is the physical limit of the digitizer's resolution. We talk about the resolution limit because we need to distinguish between resolution as a characteristic of the device and as a software-defined resolution, which is a variable in the digitizer setup. The product specification always indicates both characteristics - both the resolution limit and the accuracy.

The result of the work is also influenced by the accuracy of the operator’s actions. On average, a good operator will introduce an error of no more than 0.004 inches. The requirements for it are quite high. Pressure-sensitive digitizer technologies Currently, there are two technologies used in pressure-sensitive digitizers: the first is electromagnetic resonance, which is the basis of which Wacom digitizers work, allowing the use of a passive stylus, and the second is the active cursor method.

When using electromagnetic resonance, the emitting (active) device is the digitizer itself. The pen reflects the waves, and the digitizer analyzes this reflection in order to establish the coordinates of the pen at a given moment. Therefore, the pen or cursor does not have any batteries or a cord that supplies voltage to the microcircuits inside the cursor, they simply are not there. When using an active cursor, it is the cursor that emits waves, thus informing the digitizer of its location. In this case, either batteries or wire are its integral attribute. But, regardless of the system, in both cases information about the position of the cursor relative to the grid built into the surface of the digitizer is converted in the computer so that we receive data about the exact position of the cursor.

A serial port is usually used to connect a tablet. Common parameters are a resolution of about 2400 dpi and high sensitivity to pressure levels (256 levels). This feature allows you to simulate pressing on a brush or pen when working with the corresponding graphics programs. Graphic tablets and digitizers are produced by CalComp, Mutoh, Wacom and others.

For handwritten information input devices, the same operating scheme is typical, only the entered letter images are additionally converted into letters using a special recognition program, and the size of the input area is smaller. Pen input devices are more often used in subminiature PDA (Personal Digital Assistant) or HPC (Handheld PC) computers (see Classification of portable computers), which do not have a full keyboard.

Selecting a Digitizer

First of all, when choosing a digitizer, you should take into account the reliability of its drivers and the convenience of the pointing device (this can be a stylus or cursor). Don't forget about ergonomics.

Structurally, tablets are rigid and flexible. Flexible digitizers appeared on our market in the spring of 1994. Low price, low weight (7 kg per package), compactness during transportation distinguish them from traditional rigid ones. Its format depends on the type of work for which you choose a digitizer. The working area typically ranges from 6 x 8 inches to 44 x 62 inches. Manufacturers of flexible tablets using new technology claim that they can “cut” them into any format. Users often refer to the format by analogy with paper sheets, but the size of 305 x 305mm is difficult to relate to any standard format. The accuracy of the device depends on the type of tasks being solved. We recommend that you familiarize yourself with the parameters of digitizers and the results of comparing some of them. Electrical power for the digitizer is supplied using a built-in or remote power supply, and in some models - via a serial port.

Drivers

When working with digitizer drivers, they can work in three ways: emulating a mouse, that is, working in the relative coordinate setting mode; as a standard ADI tablet driver regardless of which device is the system one; like WinTab driver. It is known that Windows comes standard with drivers for various mice, but not for digitizers.

Pointing device

Choose your pointing device carefully. If the cursor is inconvenient, then the costs associated with its use will amount to much more than the difference in the cost of expensive and cheap digitizers.

Cursors

Cursors come in four-, eight-, twelve- and sixteen-button types. Wanting to stand out, some companies try to become the exception to the rule. So, Oce Graphics adds a seventeenth, “most important” button on the large cursor. The shape of the cursor, the ease of pressing and the placement of the buttons are the differences. All over the world, four-button cursors from CalComp are recognized as one of the best. They are most often photographed and published in magazines. On them, the second and third buttons are located next to each other, and the first and fourth L-shaped ones frame the middle ones. The diamond-shaped arrangement of buttons is considered traditional, which other well-known manufacturers continue to follow. However, for twelve- and sixteen-button cursors there is only one canon - a “tabular” arrangement of buttons, like on a telephone.

When choosing a cursor, you need to take into account, in addition to ease of use, the number of keys on it. Anyone who has worked in AutoCAD for DOS knows that the more keys on the cursor, the better, because additional buttons can be assigned one-step functions in the AutoCAD MNU file.

But for AutoCAD for Windows this is not entirely true. The fact is that using additional, more than three, keys when working in mole mode is not an easy task. To avoid problems, it is better to use special digitizer control programs, which are often included in the package. But it’s easier to abandon a cursor with a large number of buttons in favor of a four-button one and use only three of its buttons. The quality of the visor is also important in the cursor.

Feathers

As already mentioned, pens are produced with one, two and three buttons. In addition, some of them are pressure sensitive, especially attractive to computer artists and animators. This pen can perceive up to 256 levels of pressure. The degree of pressure corresponds to either the thickness of the line, or the color in the palette, or its shade. As a result, you can simulate on a computer the process of painting with oil paints, tempera or watercolors on a specially selected “texture”. To implement these capabilities, you must have special software. Among such programs for personal computers we can mention Adobe PhotoShop, Aldus PhotoStyler, Fauve Matisse, Fractal Design Painter, Autodesk Animator Pro, CorelDraw. Pressure-sensitive pens can also be useful to AutoCAD users for subsequent three-dimensional visualization of designed objects. This type of pointing device is used only with EM digitizers.

The comfort of a pen is a purely subjective characteristic, just like when choosing a fountain pen. Some people like the lightweight Wacom nibs, while others prefer the heavier but well-balanced Kurta nibs. Both cursors and pens come with or without a wire. A wireless pointer is more convenient, but it must have a battery, which makes it heavier and requires additional maintenance.

The exception is Wacom's passive non-radiative pens, which, however, perceive half as many pressure levels. Not long ago, offers appeared on the digitizer market with modifiable cursors that can work with both a wire and a battery. Time will tell how successful this decision is.

A digitizer is an encoding device that provides input of a two-dimensional (including halftone) or three-dimensional (3D digitizers) image into a computer in the form of a raster table. is a typical external specialized graphic input device.

The task of obtaining 3D models of real objects faces industrial designers, engineers, artists, animators, and game application developers. Measuring the geometry of complex spatial shapes is a fundamental requirement for modern tooling manufacturers.

Main applications of digitizers:

Animation

Digitization of geographic maps for working with geographic information systems (GIS)

Engineering design, prototyping and reverse engineering

Scientific visualization

Note: Usually the process of processing images of digitizers is called scanning (Do not confuse with a scanner!).

The simplest digitizer is a graphics tablet.

Rice. Graphics tablet

3D digitizer

Rice. 3D digitizer

One example of a full-featured solution for digitizing objects of any shape is the inexpensive digitizer from the MicroScribe-3D range manufactured by Immersion Corporation. Attached to an asymmetrical base is a three-jointed lever ending in a sensor pen. Low-friction hinges provide virtually absolute freedom of movement for the steel blade. The MicroScribe digitizer can digitize objects within a radius of up to 840 mm. The lever of the devices is rigid, the presence of hinges allows you to draw an arc with a maximum angle of 330°. The tip of the “hand” can have a different shape: in the form of a ball or a sharp needle - to take more accurate readings. The scanner also comes with foot pedals that act as right and left mouse buttons.

Rice. MicroScribe-3D digitizer.

The digitizer must be calibrated before each digitization. The user selects three reference points (front right, front left and rear right) and enters their coordinates into the computer using foot pedals. After this, you can proceed directly to digitization. Mechanical digitizers have a fairly high accuracy - up to 0.2 mm. Models from the MicroScribe-3D series can take coordinates at a speed of 1000 points per second and transmit information at a speed of 38 Kbps. Before scanning, many designers outline the object and draw lines along which the pen will pass.

Rice. Preparing an object for digitization

Digitization can be done in semi-automatic and manual modes. A contact probe mounted on a folding armature with articulated joints reads information about where the head is located and translates this information into X, Y and Z coordinates in three-dimensional space. The digitized data is further processed using special application programs (AutoCad, Autodesk, Maya, Rhinoceros, etc.).

It can take several hours to prepare for scanning and digitize a complex object itself, but with the accumulation of experience working with a digitizer, this time is significantly reduced. In the process of scanning an object, as the coordinates of the points enter the computer, a spatial model appears on the monitor. To build 3D images, you can use programs from Immersion Corporation (Digitizing Software Application), which allow you to represent scanned objects in various ways, for example, as points, lines, wireframe, splines, NURBS (non-uniform rational B-splines), and also edit and save 3D images in dxf, IGES, obj, txt, 3ds files for subsequent import into other applications.

To digitize TV-quality models, custom model specialists use more expensive digitizers to digitize their objects. For example, they use mobile coordinate measuring machines (CMMs) FaroArm manufactured by FARO Technologies (USA). FARO CMM consists of a base plate that is attached to any suitable place and several elbows connected to each other by hinges. The design is very similar to the structure of the human hand. FARO CMM also has unique wrist, elbow and shoulder joints. Each joint has an angular movement control sensor, which monitors the angle of rotation of the knee in real time, as a result of which the software calculates the coordinates of a calibrated probe - a kind of finger. Depending on the number of elbows, there are machines with 6 or 7 degrees of freedom.

Essentially, it is a touch probe that, using several potentiometers mounted on a folding armature with articulated joints, reads information about where the head is located and converts this information into X, Y and Z coordinates in three-dimensional space. It is enough to take the required number of measurements, and the grid is ready. The scanner uses a counterweight system; it automatically takes into account temperature changes and compensates for the corresponding expansion and contraction of materials. This portable device can handle objects that fit into a sphere up to 3.65 m in diameter and has an accuracy of up to 0.3 mm.

Rice. Mobile coordinate measuring machines Faro Arm

Three-dimensional digitizers are used as three-dimensional body scanning systems (3D body scan, i.e. “three-dimensional scanning of the human body”). The development of these systems was associated with the requirements of quickly measuring large numbers of people (army), obtaining an accurate computer image (film industry) and individual tailoring. Three-dimensional body scanning is also used in medicine, animation and in the creation of virtual reality systems (VRML).

Rice. WB4 body scanning system

Examples of body scanning systems

Cyberware Whole Body Color 3D Scanner (manufacturer: Cyberwear). Now there are two models of full-scale body scanners: WB4 and WBX (WB=Whole Body, i.e. “whole body”).

In geoinformatics, computer graphics, computer-aided design (CAD), cartography and scientific processing of measurement results, a digitizer is used as a device for manually digitizing graphic and cartographic information in the form of a set or sequence of points, the position of which is described by rectangular Cartesian coordinates of the digitizer plane.

Main types of digitizers based on operating principle

Ultrasonic

Of all the systems for digitizing 3D objects, ultrasonic (or sonar) are the least accurate and reliable, but at the same time the most sensitive to changes in the surrounding space. Ultrasonic digitizers are a system of transmitters rigidly mounted on walls and ceilings. They look very unaesthetic. Transmitters emit sound waves, based on information about the reflection of which the coordinates of points on the surface of a 3D model are calculated. Since the speed of sound depends on atmospheric pressure, temperature and other conditions (for example, humidity), the results of digitizing the same object are a function of the state of the air. In addition, these systems are very susceptible to noise produced by various equipment (computers, air conditioners), even the hum of fluorescent lamps affects digitization. In addition, ultrasonic systems produce strange “clicking” sounds that irritate the operator and everyone in the room. Under ideal conditions, the absolute error of the results obtained is 1.4 mm. Such scanners are used mainly in medicine and in the digitization of sculptures.

Electromagnetic

The operating principle of electromagnetic 3D digitizers is the same as that of ultrasonic systems (the radar principle), only electromagnetic waves are used instead of sound waves to build a spatial model. The results of these scanners do not depend on weather conditions, but nearby metal objects or magnetic field sources reduce the accuracy of the measurements. Naturally, such systems cannot digitize metal objects. Even in special rooms that do not contain anything metallic, the error of magnetic systems is at least 0.7 mm.

Laser

First of all, it should be noted that the price of these so-called contactless (the operator does not circle the object with the probe) systems is very high and there are often cases when it is expressed as a number with five zeros (in US dollars). Laser digitizers have the highest accuracy, but their scope of application also has significant limitations. Great difficulties arise when scanning objects with mirror, transparent and translucent surfaces, as well as large objects or those with depressions or protrusions that prevent the direct passage of the laser beam. Laser digitizers are fully automated systems. The inability of the artist to participate in the digitization process does not allow emphases to be placed, for example, to display a certain part of the object in more detail, or, conversely, leads to detailed models that take up too much space and require significant processing power. The digitization itself occurs quite quickly, but the subsequent process of translating automatically obtained data into the final image can take a lot of time (this is especially true for systems with point projection).

Mechanical

These devices are the golden mean among all classes of digitizers. High accuracy and relatively low cost have made these devices the most popular. The principle of their operation is as follows: the contours of the digitized object are traced with a precision probe, the position of which is measured by mechanical sensors. Then, using an array of three-dimensional coordinates, a special program builds a wireframe model of the object. The big advantage of mechanical scanners is that the results obtained with their help do not depend on weather conditions, noise levels, or the presence of electromagnetic fields. The type of surface also does not matter. Because mechanical digitizers are hand-held devices, their use requires careful coordination and attention.

Graphic tablets (digitizers)

Graphics tablet - a device for inputting vector graphic information into a computer. A “tablet” device (digitizer, digitizer or digitizer) consists of the tablet itself (a section of a flat surface) and a drawing device (cursor, stylus, pen, “pointer” - puck). When you press the cursor button, its location on the tablet surface is fixed, and the coordinates are transferred to the computer.

The digitizer is an absolute device. To set a certain position on the screen, you need to use the digitizer pointer to select the corresponding point on the tablet (Table 4.4).

Each button of both the pointer and the pen can be assigned certain actions (copy, save etc.) The flexibility of performing such an assignment depends on the programmability of the device driver.

The digitizer is often associated with controlling commands in AutoCAD and similar systems using overlay menus. Menu commands are located in different places on the surface of the digitizer. When the cursor selects one of them, a special software driver interprets the coordinates of the specified location, sending the corresponding command for execution.

For handwritten information input devices, the same operating scheme is typical, however, the entered letter images are additionally converted into codes using a recognition program, and the size of the input area is smaller. Pen input devices are often used in pocket computers that do not have a full keyboard.

Table 4.4. Types of Digitizers

Principle of operation	Description	Device examples
Acoustic	The first devices in which the position of a pen equipped with a sound source (micro-spark gap) is determined by comparing the delay of sound signals perceived by microphones located on the tablet. Susceptible to acoustic interference	Common name: spark tablet
Electromagnetic	A wire mesh placed under the surface of the tablet produces weak electromagnetic radiation, which is received by the pen and determines its coordinates	RAND Tablet known as Grafacon (Graphic Converter), 1964
Passive cursor	The principle of electromagnetic induction is used. The wire mesh forms a collection of “antennas” that transmit and receive signals (the RAND Tablet transmits only). There are samples that sense pressure on the pen (a change in the capacity built into the tip of the pen). Non-contact acquisition of coordinates is possible. The pen may not require power	Wacom technologies
Active cursor	The pen contains a signal generator that is sensed by the tablet, so it requires power rather than the tablet itself. This also gives a clearer electrical signal than in the case of electromagnetic induction	FinePoint Innovations
Resistive touch screen technology (see Fig. 5.28)	The intersecting coordinate wires are separated by a thin layer of insulator, the conductivity of which changes under pressure from the pen. Does not require pen power, senses both coordinates and pen pressure

Usage

computer graphics applications (especially two-dimensional). Many graphics packages (e.g. Corel Painter, Inkscape, Photoshop, Pixel image editor, Studio Artist, The GIMP) are able to interpret pen pressure (in some cases tilt), changing features such as brush size, transparency and coloring of the image based on the data, received from a graphics tablet;
In East Asia, digitizers, or pen tablets as they are called there, are used in conjunction with software like IMES (Input Method Editor Software) to input handwritten Chinese, Japanese, and Korean characters (CJK). The technology is popular and inexpensive, and companies like Twinbridge Software provide users with programs that cost less than $100;
technical drawings and computer-aided design systems - CAD (Computer Aided Design - CAD);
Finally, it is a winning alternative to such a popular pointing device as the computer mouse.

Operating principles

The operation of the digitizer is based on fixing the location of the cursor, usually using a grid built into the tablet, consisting of wire or printed conductors with a fairly large distance between them (from 3 to 6 mm). However, the mechanism for registering the cursor position makes it possible to obtain information reading accuracy that is much smaller than the grid pitch (up to 100 lines per mm). The information reading step is called resolution digitizer.

According to physical principles, digitizers are divided into three types:

electrostatic (ES);
electromagnetic (EM);
piezoelectric (PE).

In the first case, a local change in the electrical potential of the grid under the cursor is recorded. In the second, the cursor emits electromagnetic waves, and the grid serves as a receiver. It should be noted that when operating EM tablets, interference from emitting devices, in particular monitors, is possible. When you press with a pen within the working surface of the PE tablet, under which a grid of the finest conductors is laid, a potential difference arises on the piezoelectric plate, which allows you to determine the coordinates of the point. Such tablets may not require a special pen at all and allow you to draw on the working surface of the tablet as on a regular drawing board.

Regardless of the registration principle, there is an error in determining the cursor coordinates, called digitizer accuracy. This value depends on the type of digitizer and the design of its components. It is affected by the instability of the geometry of the recording grid of the tablet, the ability to reproduce the coordinates of a stationary cursor (repeatability), resistance to different temperature conditions (stability), cursor quality, noise immunity and other factors. The accuracy of existing tablets ranges from 0.005 to 0.03 inches. On average, the accuracy of electromagnetic digitizers is higher than that of electrostatic digitizers.

Table 4.5. Characteristics of digitizers

English	Russian term	A comment
	Work surface size	Sets the dimensions of the sensitive part of the digitizer surface
Degrees of freedom	Number of degrees of freedom	Describes the number of characteristics of the relative position of the tablet and pen. The minimum number of degrees of freedom is 2 (X and U position of the projection of the sensitive center of the pen), additional degrees of freedom may include pressure, tilt of the pen relative to the plane of the tablet, etc.
	Permission	Indicates the digitizer reading step (a physical characteristic, it is much better than the actually achievable accuracy of reading the coordinates of a pointing device)
	Accuracy	Indicates the error in taking coordinates
	Baud rate	Indicates the actual speed of coordinate transfer by the digitizer
	Technology	Describes the physical principle of obtaining coordinates

End of table. 4.5

English	Russian term	A comment
	Custom settings	Availability and number of digitizer parameter settings saved with the possibility of later recall
	Data formats	Typically the number of different data formats that the digitizer interface can be configured for is specified.
	Hardware menu	Number and type of hardware-implemented menus on the digitizer surface
	Indicators	The presence or absence of indicators indicating the status of the digitizer
	Software security	A variety of software included in the standard delivery of the digitizer. Usually its diversity does not mean anything. It is important to make it easy to work with the installation program and configure settings, as well as the availability of high-quality drivers for the programs you are going to work with
	orientation	Ability to switch the direction of the digitizer axes
	Guarantee	Standard warranty period
		feather. Characteristics include the number of buttons, the type of pen tip sensitivity (non-sensitive, pressure sensitive switch, etc.), the presence or absence of a wire
		Characteristics of type pointing device cursor: number of buttons, presence or absence of wire
	Coating	Availability of additional coating of the digitizer surface

Pointing device

Until now, when we mentioned a pointing device, we called it a cursor, although there is also a stylus (or stylus). Pen-shaped pens are equipped with one, two or three buttons. In addition, there are simple nibs and pressure-sensitive nibs.

Cursor. Cursors come in four-, eight-, twelve- and sixteen-button types. The products of some manufacturers are an exception to the rule, for example, Ose Graphics adds a seventeenth, “most important” button on a large cursor. One of the most popular are four-button cursors from CalComp - they are most often photographed and placed in magazines. Here, the second and third buttons are located side by side, and the first and fourth L-shaped ones frame the middle ones. The diamond-shaped button arrangement is considered traditional, which other well-known manufacturers continue to follow. However, for twelve- and sixteen-button cursors, the standard is a “tabular” arrangement of buttons (like on a telephone set).

Feather. Pens are available with one, two and three buttons. There are pressure-sensitive pens that are especially attractive to computer artists and animators. The degree of pressure corresponds to the thickness of the line, the color in the palette or its shade. As a result, you can simulate on a computer the process of painting with oil paints, tempera or watercolors on a specially selected texture. To implement these capabilities, you must have special software.

The exception is Wacom's passive non-radiative pens; however, they perceive half as many pressure levels. Models have appeared with modifiable cursors that can work with both external and built-in power.

Mouse. As accessories for some tablets, there are special mice, when used, the tablet acts as a mouse pad. Since the resolution of a tablet is usually higher than that of a regular computer mouse, using a mouse-tablet combination allows you to achieve higher accuracy when typing.

Most wireless tablet pointing devices function like a traditional mouse and have two or three buttons (usually programmable) and a scroll wheel that can be spring-loaded, have a limited rotation angle, and can be customized by software.

Snapping to tablet coordinates is a property inherent in all tablet mice without exception. Unlike conventional manipulators of the same kind, in which “up” and “down” are arbitrary and depend on the rotation of the hand, tablet mice are strictly tied to spatial references. They can be rotated around an axis as you like, but the “top” for them is always the top of the tablet, and not their own.

In table Table 4.6 shows the characteristics of some digitizer samples.

Table 4.6. Some digitizer models

	Characteristics	General view of the product
Genius G-Pen 340	Interface and power: USB. OS: MS Windows 98SE/ME/2000/XP. Tablet: working area 3" x 4"; resolution 2000 lines/inch. Pen: number of buttons - 2, pressure sensitivity -1024 levels, wireless. Has a programmable “Hot-KEY” zone. The pen buttons can function like buttons on a regular mouse, and can also be programmed to correspond to the right and left mouse buttons
Genius G-Pen 560	Interface - USB. OS - XP/2000, MacOS 10.2.5. Tablet: working area 4.5" x 6"; resolution 2000 Ipi. Pen: two programmable buttons, pressure sensitivity -1024 levels, replaceable tips, power supply - AAA battery
Genius G-Note 5000 A5, 32 Mb	Interface: USB. OS: XP/2000. Tablet: working surface A5 (8" x 6"), power supply - 4 AAA batteries, 32 MB of built-in memory allows you to save more than 500 written pages. Pen: replaceable tips

Continuation of the table. 4.6

	Characteristics	General view of the product
Wacom Graphire4, A6.128 x 93 mm	Interface: USB. OS: Windows 98SE/ME/2000/XP, Apple MacOS X 10.2.8. Tablet: work area A6 (128 x 93 mm work area), resolution 2032 lines/inch. Pen: number of buttons - 2, pressure sensitivity - 512 levels, wireless
Hitachi T-15XL EM Panel, A4+, 304 x 228 mm, TFT, 15", VGA, USB, audio	To tablet (work area A4, 304 x 228 mm) built-in monitor - 15" LCD TFT. Pitch size - 0.297 mm, maximum resolution - 1024 x 768, color palette - 18-bit (262,144 colors), brightness - 250 cd/m 2, contrast - 400: 1, left/right viewing angle - 60760°; bottom/top viewing angle - 60740°. Interfaces - VGA, HD-15F, USB Type B. Audio input - mini 3.5 mm stereo, audio output - mini 3.5 mm. stereo. Power adapter - 220 V (AC), 50/60 Hz, 30 W
Hitachi StarBoard VT-1	Interface: USB, Bluetooth. OS: Windows XP. Tablet: working area 4.5" x 6", resolution 500 dpi. Pen: number of buttons - 1
Wacom Graphire4 Classic	Interface: USB. OS: Windows 98SE/ME/2000/XP, Apple MacOS 9.0, Apple MacOS X 10.1.5. Tablet: work area A6 (128 x 93 mm), resolution 2000 dpi. Pen: number of buttons - 2, pressure sensitivity - 512 levels, wireless. Maximum working distance 5 mm. Mouse: Wacom EC-140, optical, wireless, 2 buttons, button/scroll wheel

End of table. 4.6

Control questions

1. What is the working principle of thermal inkjet printer?
2. What is the operating principle of a piezo drive inkjet printer?
3. What are the types of printer paper feeders?
4. Describe the internals of a laser printer.
5. What is the operating principle of thermal printers?
6. Describe the design and principles of operation of scanners.
7. What parameters characterize scanners?
8. What types of scanners do you know?
9. What is the operating principle of pen plotters?
10. What parameters characterize plotters?
11. What is the operating principle of laser plotters?
12. What is the operating principle of electrostatic digitizers?
13. What is the operating principle of electromagnetic digitizers?
14. What parameters characterize digitizers?

What is a digitizer used for?

Master's answer:

You can use more than just a mouse to create drawings on your computer. A special tool – a digitizer – will help you easily obtain a professionally produced image.

A digitizer (also known as a graphics tablet) is a computer peripheral device that makes it possible to draw images and graphics by hand in the same way as on paper. However, thanks to this tool, the image is converted into digital format and can be further processed on a computer.

It consists of a touch panel, a stylus (pen) and is connected to a computer for operation. And everything you draw on its surface is instantly displayed on the display. The very first device that became the progenitor of the modern tablet was the phototelegraph, created by Elisha Gray back in 1888.

Graphics tablets are used as tools for creating two-dimensional computer graphics, in which the drawn information is converted into digital information. Such tablets have the ability to record all movements of the stylus, respond to changes in its pressure, speed and angle of inclination.

Graphic tablets are very popular among artists. By combining their use with software like Adobe Photoshop, it becomes possible to create high-quality drawings and then professionally digitize them at home. And applications designed for handwriting recognition can convert handwritten letters and characters into electronically printed ones.

Large digitizers, more like drawing boards, are used for design work. You can even attach a piece of paper to them. They do not use a stylus, but a special “puck” with a magnifying glass, a cross for precise positioning and several buttons that are used to enter position coordinates and other functions. The created template is gradually processed by the software, after which the final image is generated.

) is a computer peripheral device that allows you to draw pictures and graphics by hand in the same way as on paper, but thanks to this device, the drawings are digitized and can be processed by computer.

The digitizer consists of a touch panel, a stylus (pen) and connects to a computer. Everything that is drawn on its surface is displayed directly on the computer monitor to which the device is connected. The first device, the predecessor of the modern one, was the phototelegraph, patented by Elisha Gray in 1888.

One of the important events of Sasha’s childhood was her parents. They were when the girl was five years old. And seven years later, her mother remarried, and the new family moved to the southern United States.

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Career in the porn industry

At the time, the girl Marina Ann Khentsis decided to become a porn star Sasha Gray - no one knows. In some interviews, the girl noted that issues of sexuality began to interest her from the age of eleven. The only thing that is known for sure is that the actress arrived in Los Angeles with the desire to be a porn star.

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Sasha's life now

In 2011, Sasha Gray released the book “Sex in a New Way,” which is a photo album. It shows the stages of her work in porn and the behind-the-scenes world of “adult” cinema. The second one was released in May 2013.