1、AIIM TRLS 93 W LO12348 0500355 700 W AIIM TR19-1993 Electronic Imaging Output Displays Technical Report n Association for Information and Image Management 1100 Wayne Avenue, Suite 1100 Silver Spring, Maryland 2091 O Telephone 301 1587-8202 AIIM TRIS 93 W LO12348 0500356 b47 m AIIM TR19-1993 Technica
2、l Report for Information and Image Management Electronic Imaging Output Displays Association For Information and Image Management a a This technical report describes current electronic display technologies that are used in the office document handling environment. It can be used as a guide when sele
3、cting appropriate display technology to match electronic image manage- ment requirements. AIIM TR19 93 m 1012348 0500357 583 Contents Foreword i 1 Scope and purpose .l 2 References . 1 3 Definitions . 1 4 Display technologies . 3 for one definition to be inappropriately used for another. Although th
4、e following do not comprise all technologies or situations, it is important to differentiate between the following terms for the purpose of this report. Fuller and more detailed explanations are provided in the appropri- ate sections of this technical report. O 5 Display features .5 6 Application co
5、nsiderations. . 10 7 Human factors and ergonomics 11 8 Summary . 12 Figure 1 Illustration of portrait and image landscape displays 8 Foreword This document provides information on the types ofdis- plays used with electronic image management (EIM) sys- tems. Particular emphasis has been given to high
6、- resolution monochrome displays that are used for office- type documents. Color displays have been included as well as a brief review of other emerging technologies. (Note: The terms cathode ray tube, monitor and display are commonly used. For the purpose of this technical report, the term display
7、is used.) Throughout this report, it is important to note that primarily, two types of information are displayed on a workstation terminal. The first is text and graphics creat- ed by a software application. This information is creat- ed by the software program from stored text and graphic attribute
8、 data. Text created in this manner is optimized by the display manufacturer to have the highest resolu- tion achievable by that display device. The second type of information displayed is text and graphics which are represented as a digital reproduction of a document. This information is created by
9、scanning and storing a bit-map of a document. The display quali- ty of a scanned image is directly affected by the quality and resolution of the scanner and indirectly by the qual- ity and resolution of the display device and any support- ing software that enhances the displayed image. In considerin
10、g any display device for bit-map image processing, the quality of the input must be judged. The quality and accuracy of the scanned image (a bit-mapped reproduction of a document) on any display, whether the display is high or low resolution, monochrome or color, is dependent on the condition of the
11、 original document, the quality of the scanner, and any post-scanning work done for image enhancement. Although scanning is not addressed in this document, it is important in any image system. A second factor must be noted as it relates to resolution and displays. The definition of resolution depend
12、s on how an image is being produced and it is entirely possible a. Photographic resolution: The resolution of a camera lens is typically measured by using a series of parallel lines called a test chart. The National In- stitute of Standards and Technology developed a chart in which the line width is
13、 equal to the space between the lines. As the line width and the space between the lines are reduced, the ability of the lens to differen- tiate between line and space is tested. These lines and spaces are called line pairs and are measured as line pairs per millimeter (Ip/mm). b. Computer display r
14、esolution: Information dis- played on a computer terminal is composed of a pat- tern of dots that are either lighter or darker then the background light. These dots, when combined in a series, form characters or a representation of a scanned document. The resolution of the display screen is continge
15、nt on the number of dots that can be displayed as individual dots and the capability of the display to keep the dots and open space separate. These dots are typically measured as the number of dots per inch (dpi) that a display can produce. c. Printer output resolution: Similar to a display, a laser
16、 printer lays down a pattern of dots that form an image of what is being printed. The resolution is dependent on the number of dots, horizontal and ver- tical, that can be printed in one square inch. The higher the number of dots, the smaller they are, and hence the finer the printed image can be. T
17、he human eye can then resolve this image. For example, the eye will typically be able to see the difference between printing at 100 dots per inch and 300 dots per inch. A complete discussion of resolution and factors affect- ing resolution can be found in AIIM TR26-1993, Tcch- nical Report for Infor
18、mation and Image Management, Resolution as it Relates to Photographic and Electronic Imaging. We wish to acknowledge Sigma Designs and Cornerstone Technology for their valuable help with preparing this technical report. We also wish to ac- knowledge Dr. James Sheedy of the School of Optome- try, Uni
19、versity of California at Berkeley, for providing copies of his research for use in this technical report. Suggestions for improvement of this technical report are welcome. They should be sent to the Chair, AIIM Stan- dards Board, Association for Information and Image Management, 1100 Wayne Avenue, S
20、uite 1100, Silver Spring, MD 20910. I AIIM TRL7 73 1012348 0500358 4LT M At the time it approved this technical report, the AIIM Standards Board had the following members: The AIIM Electronic Imaging/Output Committee, C14, processed and approved this technical report. The com- Marilyn Courtot, Chair
21、 Thomas C. Bagg Thomas E. Berney Loretta DAgnolo Bruce Evans Bruce A. Holroyd Don Klosterboer E. Brien Lewis Alan S. Linden Charles A. Plesums George Thoma Charles E Touchton Herbert J. White II - mittee had the following members at the time this tech- nical report was approved: Association for Info
22、rmation and Image Management National Institute of Representative Standards and Technology Shahzad Qazi, Chair Thomas Bagg Consultant American Express Company 3M Company Eastman Kodak Company Anacomp, Inc. I-NET, Inc. Wang Laboratories U SAA National Library of IBM Corporation Genealogical Society o
23、f Medicine Utah Betty Burton Jack Coplen Lindsay Eisan Donald Klosterboer Basil Manns John Stapleton Charles E Touchton Organization Eastman Kodak Company National Institute of Standards and Technology Department of the Army, Image Systems Support Di recto rate Cornerstone Technologies MIT Libraries
24、 Anacomp, Inc. Library of Congress Staplevision, Inc. IBM Corporation AIIM TRLS 93 1012348 0500357 356 Technical Report for Information and Image Management - Electronic Imaging Output Displays, AIIM TRl9-1993 1 Scope and purpose 1.1 Scope This document describes basic display technology, purchasing
25、 considerations, and ergonomic considerations for buyers and sellers evaluating electronic displays, particularly within the electronic image management (EIM) environment. 1.2 Purpose The purpose of this technical report is to provide information on various aspects of EIM display technology for user
26、s to refer to when selecting a computer display for EIM applications. 2 References AIIM TR2-1992, Technical Report for Information and Image Management, Glossary of Imaging Technology. AIIM TR26-1993, Technical Report for Information and Image Management, Resolution as it Relates to Photo- graphic a
27、nd Electronic Imaging. VDTS and Vision Complaints: A Survey. James Sheedy, Information Display, ApriVMay 1992, Vol. 8, No. 4 voltage varies continuously. Capable in theory of displaying an infinite number of shades of the primary colors. 3.5 Antiglare filters: A method of coating the face of the vid
28、eo display tube with anti-glare material; placing an anti-glare screen in front of the face of the display tube; or etching the glass surface of the display tube to reduce glare. 3.6 Blooming: As light intensity and the spot size increase, the display will track over one scan line onto the adjacent
29、lines. This will vary from the center of the screen to the corner. 3.7 Board: Refers to the adapter or controller board in a computers backplane that provides the interface circuitry between the computer and display (in displays). 38 Brightness: Perception of the amount of light a display emits, ref
30、lects, or transmits. This can be measured as an average over an area or as pixel spot- brightness. 3.9 CGA: See color graphics adapter, 3.17. 3.10 CFF: See critical flicker frequency, 3.18. 3.il CRT See cathode-ray tube, 3.12. 3.12 Cathode ray tube (CRT): Signal-to-image converter tube in which a we
31、ll defined and controllable beam of electrons is produced and directed onto a surface to give a visible or otherwise detectable display or effect. 3.W Color, continuous tone: Ability of the display to produce a range of colors or varying shades of the same color. The color range is dependent on the
32、number of bits assigned to each primary color. For example, if each primary color (red, green, blue) was capable of 256 levels of color, the display would be capable of producing 16 million colors. 3.14 Color display: Display capable of presenting colors perceived as a function of the three major su
33、bjective attributes of hue, saturation and intensity (HSI). 3.15 Color, saturated: Vivid primary colors red, green, blue (RGB) and their respective complements cyan, magenta, yellow (CMY) undiluted by white or other colors which reduce the purity as indicated by the AIIM TRLS 93 = LO12348 0500360 07
34、8 locus of points on the CIE and UCS chromaticity diagram. Note: cyan is equal to minus red, yellow is equal to minus blue, magenta is equal to minus green. 3.16 Contrast: Ratio of the difference between on pixel brightness and the surrounding background or of pixel brightness to the average or spec
35、ified background reflection of ambient illumination. The greater the brightness, the greater the contrast difference must be to result in the same perceived contrast ratio. 3.17 Color graphics adapter (CGA): The first color video interface set of requirements established for IBM PCs. Uses analog and
36、 digital video signal. Resolution was 320 dpi x 200 dpi. Superseded by EGA. 3.18 Critical flicker frequency (CFF): Frequency at which a flicker becomes perceptible to the eye. 3.19 DPI: See dots per inch, 3.22. 3.20 Data rate: Speed of the video controller processing bits of data. Expressed in megah
37、ertz (MHz) or millions of times per second. 3.21 Display: Visual presentation. 3.22 Dots per inch: Measurement of resolution, e.g., 200 dpi or 1,600 dpi x 1,200 dpi. See also pixel, 3.47. 3.23 Dot pitch: Spacing between picture elements (pixels) in a display; dot pitch of color triads is the distanc
38、e in millimeters (mm) between the phosphor triads and is a measure of the resolution capabilities of the display itself. Many EGA displays have dot-pitch measurements in the 0.31 mm range (or greater) and the trend is toward finer dot pitch of 0.28 mm or less. See triads, 3.5.9. 3.24 EGA: See enhanc
39、ed graphics adapter, 3.25. 3.25 Enhanced graphics adapter (EGA): EGA is the next level of increased screen clarity and resolution beyond CGA. EGA uses digital video signal transmission. Superseded by VGA. 3.26 Flat tension mask (FTM): Tightly stretched steel that is much thinner than other masks use
40、d in displays. Fewer electrons are absorbed by the mask and result in less distortion as the mask heats up. See mask, 3.3.8. 3.27 Flicker: Change in the perceived brightness of the screen caused by a low refresh rate interaction with the integration time and persistence of the eye. See also critical
41、 flicker frequency, 3.18. 3.28 GUI: See graphical user interface, 3.29. 3.29 Graphical user interface (GUI): Software that allows users to interact with a computer on the basis of graphics rather than text and menu. GUIS are based on graphical icons to represent program functions rather than typing
42、a command. 3.30 Grey scale: Capability to display varying levels of grey and usually represented as a number such as 16 levels of grey. The grey levels are created by varying the strength of the electron beam. The higher the Icvel of greyscale, the smoother the transition from light to dark. 3.31 Hz
43、 (Hertz): Measure of frequency also expressed as cyclesisec, pixelsisec, linesisec, fieldsisec, etc. 3.32 Horizontal rate: Total number of raster lines per frame times the number of frames a display draws or refreshes per second. Expressed as a frequency, e. panning moves the imagc horizontally. 3.5
44、6 Shadow masks: Used in color displays to direct the electron beam. The mask is a thin perforated metal sheet attached to the inside front of the vacuum tube. The perforations line up with the RGB phosphors. 3.57 Spot size: Dimensions of the spot or pixel being illuminated by the electron beam. A go
45、od monitors spot size will remain constant from the center of the screen toward the edge of the screen, but 10% - 20% spot growth is usually acceptable. 3.58 Super video graphics adaptor (SVGA): A resolution of 800 dpi x 600 dpi on a display device. Typical VGA resolution is 640 dpi x 480 dpi. See a
46、lso video graphics adaptor, 3.61. 3.59 Triads: Triads are sets of red, green, and blue phosphors used in color displays. I 3.60 VGA: See video graphics adaptor, 3.61. 3.61 Video graphics adaptor: Graphics requirements for the IBM PSI2 and compatibles, but with a higher resolution of pixels and color
47、s than EGA and CGA. Uses analog signal. Standard resolution is 640 dpi x 480 dpi. 3.62 Zoom: Enlarges the presentation size of information (such as text or images) on a display. A zoom feature allows the user to enlarge an area of a page (.e., an area that contains fine print) to make it more readab
48、le. 4 Display technologies This section provides a basic description of the display and display adapter card. The display is a light emitting device that is able to represent data, such as alphanumeric characters, by selectively illuminating dots on its surface to form each character. The display it
49、self is not an intelligent device and displays only input from the display adapter card. The data on a display, whether it be text, vector graphics, or bit-mapped representations, is controlled by the display adapter card hardware and software. The adapter card converts computer data into an analog or digital signal that is used by the display to create data representations. Display devices, other than CRT, are discussed but are not recommended for todays EIM systems. These alternative technologies currently do not equal the price performance of a CRT and specifically, do not have the r
