ANSI INCITS 182-1990 Information Systems - Bar Code Print Quality - Guideline.pdf

1、ANSI INCITS 182-1990 (R2002) (formerly ANSI X3.182-1990 (R2000)for Information Systems Bar Code Print Quality GuidelineAmericanNationalStandardApproval of an American National Standard requires review by ANSI that therequirements for due process, consensus, and other criteria for approval havebeen m

2、et by the standards developer.Consensus is established when, in the judgment of the ANSI Board of StandardsReview, substantial agreement has been reached by directly and materiallyaffected interests. Substantial agreement means much more than a simplemajority, but not necessarily unanimity. Consensu

3、s requires that all views andobjections be considered, and that a concerted effort be made toward theirresolution.The use of American National Standards is completely voluntary; their existencedoes not in any respect preclude anyone, whether he has approved the standardsor not, from manufacturing, m

4、arketing, purchasing, or using products, processes,or procedures not conforming to the standards.The American National Standards Institute does not develop standards and will inno circumstances give an interpretation of any American National Standard.Moreover, no person shall have the right or autho

5、rity to issue an interpretation ofan American National Standard in the name of the American National StandardsInstitute. Requests for interpretations should be addressed to the secretariat orsponsor whose name appears on the title page of this standard.CAUTION NOTICE: This American National Standard

6、 may be revised orwithdrawn at any time. The procedures of the American National StandardsInstitute require that action be taken periodically to reaffirm, revise, or withdrawthis standard. Purchasers of American National Standards may receive currentinformation on all standards by calling or writing

7、 the American National StandardsInstitute.Published byAmerican National Standards Institute11 West 42nd Street, New York, New York 10036Copyright 1990 by Information Technology Industry Council (ITI)All rights reserved.No part of this publication may be reproduced in anyform, in an electronic retrie

8、val system or otherwise,without prior written permission of ITI, 1250 Eye Street NW,Washington, DC 20005.Printed in the United States of AmericaANSI X3.1 82-1990 American National Standard for Information Systems - Bar Code Print Quality - Guideline Secretariat Computer and Business Equipment Manufa

9、cturers Association Approved March 30, 1990 American National Standards Institute, Inc American pp A roval of an American National Standard requires verification by ANSI that the National requirements for due process, consensus, and other criteria for approval have been met by the standards develope

10、r. Standard c onsensus is established when, in the judgment of the ANSI Board of Standards Review, substantial agreement has been reached by directly and materially affected interests. Substantial agreement means much more than a simple majority, but not necessarily unanimity. Consensus requires tha

11、t all views and objections be considered, and that a concerted effort be made toward their resolution. The use of American National Standards is completely voluntary; their existence does not in any respect preclude anyone, whether he has approved the standards or not, from manufacturing, marketing,

12、 purchasing, or using products, processes, or procedures not conforming to the standards. The American National Standards Institute does not develop standards and will in no circumstances give an interpretation of any American National Standard. Moreover, no person shall have the right or authority

13、to issue an interpretation of an American National Standard in the name of the American National Standards Institute. Requests for interpretations should be addressed to the secretariat or sponsor whose name appears on the title page of this standard. CAUTION NOTICE: This American National Standard

14、may be revised or withdrawn at any time. The procedures of the American National Standards Institute require that action be taken periodically to reaffii, revise, or withdraw this standard. Purchasers of American National Standards may receive current information on all standards by calling or writi

15、ng the American National Standards Institute. Published by American National Standards Institute 1430 Broadway, New York, New York 10018 Copyright 0 1990 by American National Standards Institute All rights reserved. No part of thii publication may be reproduced in any form, in an electronic retrieva

16、l system or otherwise, without prior written permission of the publisher. Printed in the United States of America APSlM1090IB Foreword (This Foreword is not part of American National Standard X3.182-1 990 ) This standard applies to the quality control parameters and procedures necessary for the eval

17、uation of the optical characteristics of a printed bar code symbol. It defines the optical characteristics and parameters to be measured, the methodology for their measurement, and a grading system to evaluate their performance in final use. This document is intended to be used alone as a guide for

18、establishing bar code testing procedures, in the creation of the print quality portions of new bar code application specifica- tions, or with existing bar code application specifications. There are two annexes in this standard. Annex A is normative and is considered part of this standard; Annex B is

19、 informative and is not considered part of this standard. Requests for interpretation, suggestions for improvement or addenda, or defect reports are welcome. They should be sent to the X3 Secretariat, Computer and Business Equipment Manufacturers Association, 311 First Street, NW, Suite 500, Washing

20、ton, DC 20001-2178. This standard was processed and approved for submittal to ANSI by Accredited Standards Committee on Information Processing Systems, X3. Committee approval of the standard does not necessarily imply that all members voted for its approval. At the time it approved this standard, th

21、e X3 committee had the following members: Richard Gibson, Chair Donald C. Loughry, Vice-Chair Jean-Paul Emard, Administrative Secretary Organization Represented Name of Representative Allen-Bradley Company . . . . . . . . . . . . . . . . . . . . . . . . Ronald H Reimer American Library Association .

22、 . . . . . . . . . Paul Peters American Nuclear Society . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Geraldine C Main AMP, Inc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 . . . . . . . . . . . . . . Edward Kelly Patrick Lannon (Ah) App

23、le Computer, Inc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Karen Higginbottom Michael J Lawler (Ah) Apple Professional Users Exchange (APUE) . . . . . . Ira Wilson Association of the Institute for Certification of Computer Professionals . . . . . . . . . . . Kenneth Zemrowski Eugene

24、M Dwyer (Alt) AT b) tolerances built into decoding algorithms; c) the ability of operators to rescan if the first read is unsuccessful; d) the availability of scanning devices that provide for multiple, unique scan paths across the code. The different symbol grades indicate print quality. An applica

25、tion specification shall identify the minimum acceptable grade level including the measuring aperture and nominal wavelength(s). Symbols with a grade of A are the best quality and will in general give the best performance. In general, this grade symbol is appropriate for systems in which the reader

26、crosses the symbol once or is limited to a single path. A symbol with a grade of 6 may not perform to the same level as one with a grade of A. Some of these B symbols may need to be rescanned. In general, this grade is best suited for applications which require symbols to be read most of the time in

27、 a single pass of a bar code scanner but allow for rescan. 13 ANSI X3.182-1990 Symbols of grade C mayrequire more rescans than those of grade B. In general, these grade C symbols may need more frequent rescanning and for best read performance a device that provides for multiple, unique scan paths ac

28、ross the code should be used. A symbol of grade D is best read by bar code readers that provide for multiple, unique scan paths across the symbol. There may be symbols with a D grade that certain readers can not read. Prior to selection of a grade D symbol for a particular application, it is advised

29、 that the symbol(s) should be tested with the type of bar code reader expected to be used. The test(s) will establish that the read results are within acceptable limits and expectations. 5.3.3 Sampling methods and levels Sample size shall be sufficiently large to be statistically valid within the si

30、ze of the lot or batch being inspected. Acceptable quality levels (AQL) shall be established prior to quality control inspection. MIL-STD-105D provides useful guidelines for statistically valid sampling plans. 6. Alternate measurements The profile reflectance technique described in this standard is

31、the preferred measurement method. Since quality inspection methods using print contrast signal (PCS) and dimensional tolerances have historic precedence, they may be used. The profile reflectance technique more closely represents the nature of bar code scanning than the historic methods based upon P

32、CS and dimensional tolerances. When traditional values are used for print quality evaluation, symbols that offer good, reliable performance may fail PCS, or dimensional tolerances, or both. 6.1 Print contrast signal (PCS) When using PCS-based methods, it is recommended that the reflectance values us

33、ed in arriving at a PCS value be taken from the bar code elements. The minimum PCS should be 75 percent. Typically, the percent reflectance of the substrate or spaces within a bar code symbol are required to be a minimum of 50 percent when symbols are printed where the nominal narrow elements are 0.

34、020 inch (0.0508 mm) or less, and a minimum of 25 percent when bar code symbols are to be printed where the nominal narrow elements are greater than 0.020 inch (0.0508 mm). The minimum reflectance within any space or quiet zone is 25 percent. The maximum reflectance of any bar is 25 percent. It shou

35、ld be noted that these two limiting factors may not be reached simultaneously. 6.2 Dimensional tolerances Historical bar code measurement methods define arbitrary dimensional tolerances of elements or measured distances. The decodability method in this guideline allows for graded allocation of the t

36、olerance between the printing process and the barcode reader. Therefore, use of the decodability method is preferred. Because of historical precedence, dimensional tolerances may be used instead of scan profile measurements. When using dimensional measurement methods, it is recommended that the mult

37、iple pass scan criteria described in 5.3.2.1 be used. 7. Additional factors affecting print quality 7.1 Substrate 7.1 .l Porosity Substrates with a high degree of porosity could affect the print quality of a bar code symbol by causing the printed image to spread outside the required bar and space di

38、mensional limits or by causing uneven absorption or specular reflection of the scanning beam. 14 ANSI X3.182-1990 7.1.2 Smoothness Smoothness is a description of the textural characteristics of a substrate (i.e., the flatness of the substrate). Very smooth surfaces tend to be difficult to print on w

39、ith some printing methods, due to image transfer and stability problems. Very coarse substrates tend to produce irregularities in the printed bars that may cause reading problems in certain applications where high-density bar codes are chosen. The proper degree of smoothness should be determined by

40、evaluating the bar code symbol in its final configuration form for each application. 7.1.3 Gloss The effect of gloss varies with different barcode scanning techniques. Therefore, when evaluating the gloss value, the maximum acceptable value is to be established by the individual application requirem

41、ents. 7.1.4 Grain The orientation of the bar code symbol to any substrate grain can affect bar code measurements, or readability, or both. 7.1.5 Opacity Show-through may adversely affect readability when a symbol is affixed over a high-contrast interfering pattern such as another bar code symbol. In

42、 such applications, when the symbol cannot be measured in its final configuration, the problems associated with show-through will be reduced if the minimum substrate opacity is 85 percent and if the maximum opacity variation is 6 percent. 7.2 Over-laminate 7.2.1 Opacity The opacity of a laminate sha

43、ll not be sufficient to attenuate or interfere with the reflected light from the scanner enough to cause the bar code symbol to be out of the required specification. The ultimate determination as to whether the effects of opacity in the laminate are significant or not shall be made by examination of

44、 the laminated bar code symbol in its final configuration for its intended application. Polarized laminates may cause scanning difficulty when readers that are sensitive in this area are used. 7.2.2 Gloss (optical effects) High-gloss laminates tend to require that scanners be positioned at angles ot

45、her than at 90 degrees (perpendicular) to the surface of the bar code symbol in order to obtain sufficient signal for proper decoding. Matte laminates tend to be less restrictive with regards to scanning angle positioning. However, they can also distort or enlarge the printed symbol to the scanner.

46、7.2.3 Smoothness (physical effects) Textured laminates can cause problems with some wand scanners if the degree of texture is great enough to be detected. Uneven application of adhesive on the laminate or trapped air bubbles between the substrate and the laminate may also create variances in reflect

47、ances and dimensional attributes of the bar code symbol as perceived by a scanner. 7.3 Environmental effects Numerous environmental factors may lead to degradation of the substrate, image, adhesive, or laminate, or any combination thereof. This degradation may affect one or more reflectance paramete

48、r(s). The net effect of degradation will be a reduction in the grade level of a symbol and may even lead to a symbol being unreadable. Environmental factors that may cause degradation include temperature, humidity, light exposure, abrasion, chemicals, and aging. Table 5 provides a list of some of th

49、e environmental factors of concern, defines some of the application areas affected by these factors, and recommends user actions which may be appropriate. ANSI X3.1 82-l 990 Table 5 - Environmental factors Environmental factor Application examples Recommended action Temperature Humidity Salt Spray Light (Ultraviolet) Abrasion Shipping Chemicals Various (industry and application dependent) Solvents 288Z dimension is 0.010” and N*Z is 0.030”, creating an RT of Within the character a narrow element has increased to 0:0135” (e) and a wide element has decreased to 0.0265” (E), the maximum d