1、 g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58Description and use ICS 37.080Micrographics ISO character and ISO test chart No. 1 BRITISH STANDARD
2、BS ISO 446:2004BS ISO 446:2004This British Standard was published under the authority of the Standards Policy and Strategy Committee on 28 April 2006 BSI 2006ISBN 0 580 48170 0Cross-referencesThe British Standards which implement international publications referred to in this document may be found i
3、n the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online.This publication does not purport to include all the necessary provisions of a contract. Users are responsib
4、le for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations.Summary of pagesThis document comprises a front cover, an inside front cover, the ISO title page, pages ii to v, a blank page, pages 1 to 7 and a back cover.The BSI copyright
5、notice displayed in this document indicates when the document was last issued.Amendments issued since publicationAmd. No. Date CommentsA list of organizations represented on this subcommittee can be obtained on request to its secretary. present to the responsible international/European committee any
6、 enquiries on the interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK.National forewordThis British Standard reproduces verbatim ISO 446:2004 and implements it as the UK national standard. It s
7、upersedes BS 4189:1967 which is withdrawn.The UK participation in its preparation was entrusted by Technical Committee IDT/1, Document management applications, to Subcommittee IDT/1/1, Quality, which has the responsibility to: aid enquirers to understand the text;Reference numberISO 446:2004(E)INTER
8、NATIONAL STANDARD ISO446Third edition2004-03-15Micrographics ISO character and ISO test chart No. 1 Description and use Micrographie Caractre ISO et mire ISO N 1 Description et utliisation BS ISO 446:2004ii iiiContents Page Foreword iv Introduction v 1 Scope 1 2 Normative references . 1 3 Terms and
9、definitions. 1 4 Description and use of the ISO character 2 4.1 Description 2 4.2 Use 2 5 Production of ISO test chart No. 1 2 5.1 Base 2 5.2 Test chart lay-out 4 5.3 Density-measuring areas . 6 5.4 Identification 6 5.5 Certification of ISO No. 1 test charts 7 6 Procedure for using ISO test chart No
10、. 1 7 6.1 Method 7 6.2 Density of the film . 7 6.3 Legibility control . 7 BS ISO 446:2004iv Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried
11、out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO
12、collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare Internationa
13、l Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the eleme
14、nts of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 446 was prepared by Technical Committee ISO/TC 171, Document management applications, Subcommittee SC 1, Quality. This third edition cancels and replaces the
15、 second edition (ISO 446:1991), which has been technically revised. BS ISO 446:2004vIntroduction Most processes produce images of lower quality; among others diffusion transfer, if it still exists, is capable of enhancing quality. This degradation may go so far as to make the information illegible.
16、Poor legibility may also cause visual fatigue after prolonged viewing. The legibility of an image can be assessed by measuring the limit of resolution, i.e. the ability to distinguish lines in different directions. However, the limit of resolution corresponds to a quality level insufficient to permi
17、t easy reading, and to prolong it without visual fatigue. A criterion which better simulates actual working conditions was sought. The ISO character, which is a conventional character similar to typefaces used in the printing industry, the outline and details of which should be distinguished without
18、 difficulty, meets these requirements. The main practical applications of the ISO character are based on the following experimental properties. a) If a particular reproduction process gives an identifiable image from a group of ISO characters of a certain height, it can be assumed that the same proc
19、ess will produce, from a printed text of comparable typeface size, a satisfactory image and, in particular, one that is sharp enough to be read, without undue visual fatigue for the viewer. b) In general, the identification of the same limiting group of ISO characters by different observers gives su
20、bstantially identical results. Care should be taken when referencing this International Standard in other standards. Some countries do not use this standard or use alternative standards (such as ISO 3334:1989, Micrographics ISO resolution test chart No. 2 Description and use). BS ISO 446:2004blank1M
21、icrographics ISO character and ISO test chart No. 1 Description and use 1 Scope This International Standard specifies the characteristics of the black and white ISO character and of the ISO test chart No. 1, as well as their use. It applies to the quality control of the microimages produced with a g
22、iven micrographic system and the assessment of the potential legibility of the documents recorded using that system. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated ref
23、erences, the latest edition of the referenced document (including any amendments) applies. ISO 3:1973, Preferred numbers Series of preferred numbers ISO 5-2:2001, Photography Density measurements Part 2: Geometric conditions for transmission density ISO 5-3:1995, Photography Density measurements Par
24、t 3: Spectral conditions ISO 5-4:1995, Photography Density measurements Part 4: Geometric conditions for reflection density ISO 2471:1998, Paper and board Determination of opacity (paper backing) Diffuse reflectance method ISO 6196-1:1993, Micrographics Vocabulary Part 1: General terms 180 6196-2:19
25、93, Micrographics Vocabulary Part 2: Image positions and methods of recording ISO 6196-3:1997, Micrographics Vocabulary Part 3: Film processing ISO 6196-4:1998, Micrographics Vocabulary Part 4: Materials and packaging ISO 6196-5:1987, Micrographics Vocabulary Part 5: Quality of images, legibility, i
26、nspection ISO 6196-6:1992, Micrographics Vocabulary Part 6: Equipment ISO 6200:1999, Micrographics First generation silver-gelatin microforms of source documents Density specifications and method of measurement 3 Terms and definitions For the purposes of this document, the terms and definitions give
27、n in ISO 6196 apply. BS ISO 446:20042 4 Description and use of the ISO character 4.1 Description The ISO character is a conventional character, similar to printing typefaces, the shape and size of which is specified below. It consists of a regular octagon, of a given height c, with two internal para
28、llel lines, the width of lines and spaces being c/7 (see Figure 1). The tolerances of c are specified in 5.2.2. Figure 1 Enlarged drawing of the ISO conventional character for legibility test The internal lines may be oriented in four different ways: vertically, horizontally, 45 to the right, and 45
29、 to the left. This orientation is defined by one of the following terms: Vertical Horizontal Right-inclined Left-inclined 4.2 Use The ISO character may be used in micrographics for making black and white or colour test charts for the quality control of microform production equipment, or microtest ch
30、arts for use with viewing and printing equipment. It may also be used for controlling the quality of images produced with other techniques (photography, reprography, etc.). 5 Production of ISO test chart No. 1 5.1 Base The test chart shall be made on either an opaque or a transparent base. BS ISO 44
31、6:200435.1.1 Opaque base The test chart shall be made on a white opaque base (preferably glossy). Its visual diffuse reflection density, measured in accordance with ISO 5-3 and ISO 5-4, shall be not more than 0,08. Its opacity, measured as specified in ISO 2471, shall be greater than 85 %. This test
32、 chart shall be positive-appearing. 5.1.2 Transparent base The test chart shall be made on a non-coloured transparent base having a maximum visual diffuse transmission density, base + fog, of 0,08 measured in accordance with ISO 5-2 and ISO 5-3. This test chart may be positive-appearing or negative-
33、appearing. BS ISO 446:20044 5.2 Test chart lay-out ISO test chart No. 1 consists of groups of ISO characters arranged as shown in Figure 2. NOTE The numbers shown in this figure are the values given in 5.2.2 divided by 10 m. This illustration is not to be used for testing. Figure 2 Sample layout of
34、ISO test chart No. 1 BS ISO 446:200455.2.1 Group of characters Each group comprises four ISO characters of the same size, each of different orientation (see 4.1). The characters shall be arranged in a square pattern as shown in Figure 3 and shall be oriented randomly. The minimum space between two c
35、haracters, horizontally and vertically, shall be 2c/7. The minimum space between two groups of characters shall be 2c/7 of the smallest character of the two groups. Figure 3 Examples of groups of ISO characters 5.2.2 Sizes of characters Dimension c, in micrometres, of the four characters of each gro
36、up shall be established by reference to the R 20 series of preferred numbers specified in ISO 3: 450 500 560 630 710 800 9001000 1120 1250 1400 1600 1800 20002250 2500 2800 The white and black lines within each group of four characters shall have the same widths, with a tolerance of 7 m, measured on
37、 each character segment (see Figure 4). However, the maximum tolerance on these dimensions (c/7) shall be 2 %. 5.2.3 Contrast The minimum visual diffuse density difference between the base and the characters shall be 3,0 for test charts on a film base and 1,6 for test charts on paper. BS ISO 446:200
38、46 Figure 4 Measurement of line width The visual diffuse density of the white lines in the ISO character should be not more than 0,02 greater than the visual diffuse density of the paper. 5.2.4 Identification of the groups of characters Each group is identified by a number, placed at the bottom of t
39、he group, corresponding to the size of the characters it contains. For example, number 45 corresponds to a group composed of characters with dimension c of 0,45 mm in size. The numbers shall be legible to the naked eye. The size of the numbers corresponding to characters smaller than 125 shall be gr
40、eater than those of the corresponding characters. 5.3 Density-measuring areas To check that the test chart meets the requirements of 5.2.3, it shall include two areas, a clear one for measuring the background density of the test chart, and a dark one, the density of which shall be considered to be e
41、qual to that of the characters. Each area shall be at least 10 mm 10 mm. These areas are identified as A and B in Figure 2. NOTE These areas are not used for measuring the densities of the microimages (see 6.2). 5.4 Identification The words “ISO test chart No. 1“, a reference to this International S
42、tandard or to any equivalent national standards and the certifying agent1), or source of issue shall appear on the test chart. 1) Test charts certified to conform to this International Standard can be obtained from AFNOR, 11, avenue Francis-de-Pressens, F-93571 Saint-Denis La Plaine Cedex, France. T
43、el: +33 (0)1 41 62 80 00. Fax: +33 (0)1 49 17 90 00. Web site: http:/www.afnor.fr BS ISO 446:200475.5 Certification of ISO No. 1 test charts Only test charts complying in every respect with this International Standard and verified by a qualified laboratory can be designated as ISO No. 1 test charts.
44、 6 Procedure for using ISO test chart No. 1 6.1 Method Position ISO test charts within the microfilming area so as to test the whole field of view. As a minimum, this shall be in the centre and the four corners. Make test exposures using the same film and processing conditions as will be used in pro
45、duction. 6.2 Density of the film Measure the background visual diffuse transmission density of the microimages of the test chart in accordance with ISO 6200. When positive-appearing test charts are used, this density shall be 1,60 0,10. 6.3 Legibility control Examine the microimages of the ISO test
46、chart No. 1 with a microscope of magnification 30 to 50, fitted with a lens having a numerical aperture of at least 0,1. A group of ISO characters of a given size considered in any area of the microimage shall be regarded as “read” if, within each character, all black and white lines are discernible
47、 and without discontinuity. Figure 5 gives examples of characters “read” and “nonread”. The minimum sizes of the characters which are “read” vary in relation to the reduction ratios used. READ NONREADFigure 5 Examples of characters “read” and “nonread” BS ISO 446:2004BS ISO BSI389 Chiswick High Road
48、LondonW4 4AL446:2004BSI British Standards InstitutionBSI is the independent national body responsible for preparing British Standards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter.RevisionsBritish Standards are updated by amendmen
49、t or revision. Users of British Standards should make sure that they possess the latest amendments or editions.It is the constant aim of BSI to improve the quality of our products and services. We would be grateful if anyone finding an inaccuracy or ambiguity while using this British Standard would inform the Secretary of the technical committee responsible, the identity of which can be found on the inside front cover. Tel: +44 (0)20 8996 9000. Fax: +44
