The purpose of this test is to measure the profile of a line on
\nthe face of a shadow mask or other structured screen cathode ray
\ntube (CRT) in order to estimate the resolution capacity of the CRT.
\nSince the display on a CRT usually consists of a series of lines or
\nline segments forming alphanumeric characters or graphics patterns
\nthe line width is an important parameter in the determination of
\nthe resolution. For this reason, the test method discussed below
\nmeasures the horizontal and vertical (and possibly diagonal)
\nprofiles of the lines produced by the electron beam or beams. From
\nthese profiles, the line widths can be determined. Only one gun of
\na mutiple gun CRT is measured at a time. Such a test for
\ndetermining the size of the CRT spot is the first step in any
\nresolution calculation. Note that line profiles can also be
\ndetermined from measurements of the intensity contours of the CRT
\nspot. This method of determining the line profile is not discussed
\nin this document.<\/p>\n
The line profile of the CRT spot is dependent on a number of
\nfactors in addition to the focused electron beam distribution at
\nthe screen. Some of these factors are:<\/p>\n
1. Electron scattering in the screen and support structure<\/p>\n
2. Light scattering due to the granular nature of the phosphor
\nand the aluminum backing of the screen<\/p>\n
3. Saturation of the phosphor<\/p>\n
4. Internal reflections and absorption of light in the faceplate
\nand panels mounted onto the faceplate<\/p>\n
5. Optical coatings, etches, etc., on the faceplate or panel<\/p>\n
6. Static or dynamic convergence of the beams in multiple beam
\ntubes<\/p>\n
External influnces on the resolution of the CRT, including
\nambient light, are not discussed in this method. These include the
\nthe transfer characteristics of the viewing system, in particular,
\nthe nonlinear response of a human observer.<\/p>\n
Determination of the resolution of a structured screen CRT is a Line Profile Measurements in Shadow Mask and Other Structured Screen Cathode Ray Tubes<\/b><\/p>\n
\ncomplex problem which is not completely solved at the present time.
\nThe limiting resolution of the tube can, in some cases, be
\nestimated by referring to the conclusions reported in recent
\npapers. For a shadow mask color CRT, the resolution is strongly
\ndependent on the pitch of the shadow mask. Kojima1<\/sup> and
\nBarten2,3<\/sup> suggest that for a dot screen CRT the spot
\ndiameter at 5% of peak brightness should be 2.5-2.6 times the
\nshadow mask pitch( the center to center distance between nearest
\nneighbor mask holes ). The same relation seems to hold for line
\nscreen tubes where the pitch is the horizontal distance between the
\nmask slots. For beams smaller than this, moire patterns are
\nproduced. In addition to the references above, a short bibliography
\nis attached. The reader is urged to consult these references and
\nthe current literature before making any conclusions about the
\nresolution of a structured screen display.<\/p>\n","protected":false},"excerpt":{"rendered":"\n\n
\n Published By<\/td>\n Publication Date<\/td>\n Number of Pages<\/td>\n<\/tr>\n \n ECIA<\/b><\/a><\/td>\n 1987<\/td>\n 10<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"featured_media":556859,"template":"","meta":{"rank_math_lock_modified_date":false,"ep_exclude_from_search":false},"product_cat":[2649],"product_tag":[],"class_list":{"0":"post-556850","1":"product","2":"type-product","3":"status-publish","4":"has-post-thumbnail","6":"product_cat-ecia","8":"first","9":"instock","10":"sold-individually","11":"shipping-taxable","12":"purchasable","13":"product-type-simple"},"_links":{"self":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product\/556850","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/types\/product"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media\/556859"}],"wp:attachment":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media?parent=556850"}],"wp:term":[{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_cat?post=556850"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_tag?post=556850"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}