{"id":354,"date":"2022-01-10T10:23:10","date_gmt":"2022-01-10T10:23:10","guid":{"rendered":"http:\/\/learnlearn.uk\/igcsecs\/?page_id=354"},"modified":"2022-01-25T07:19:51","modified_gmt":"2022-01-25T07:19:51","slug":"barcode-scanners","status":"publish","type":"page","link":"https:\/\/learnlearn.uk\/igcsecs\/barcode-scanners\/","title":{"rendered":"Barcode Scanners"},"content":{"rendered":"<div class=\"responsive-tabs\">\n<h2 class=\"tabtitle\">Introduction<\/h2>\n<div class=\"tabcontent\">\n\n<h3>Barcode Readers<\/h3>\n<div id=\"attachment_1733\" class=\"wp-caption alignright\" style=\"width: 153px;\"><\/div>\n<p>With the rapid growth of a consumer society in post-war America there grew a demand for technologies that would improve the efficiency of stock control and sales of goods. The first patent for barcodes was issued in 1951, for a circular barcode. Adapted from Morse code and using variable thickness rings it was a revolution waiting to happen. Unfortunately, due to a number of reasons it was another 20 years before the technology took off with a linear barcode version developed by IBM.\u00a0<a href=\"http:\/\/learnlearn.uk\/igcseict\/wp-content\/uploads\/sites\/3\/2016\/08\/barcode-scanner.png\"><img decoding=\"async\" loading=\"lazy\" class=\"wp-image-1733 alignright\" src=\"https:\/\/learnlearn.uk\/igcseict\/wp-content\/uploads\/sites\/3\/2016\/08\/barcode-scanner.png?_t=1618364933\" alt=\"barcode scanner\" width=\"153\" height=\"213\" \/><\/a><\/p>\n<p>This technology originally consisted of :<\/p>\n<ul>\n<li>A barcode scanner<\/li>\n<li>A printed barcode, located on a product.<\/li>\n<\/ul>\n<h3>Barcode Scanning<a href=\"http:\/\/learnlearn.uk\/igcseict\/wp-content\/uploads\/sites\/3\/2016\/08\/barcode.png\"><img decoding=\"async\" loading=\"lazy\" class=\"size-medium wp-image-1734 alignright\" src=\"https:\/\/learnlearn.uk\/igcseict\/wp-content\/uploads\/sites\/3\/2016\/08\/barcode.png\" alt=\"barcode\" width=\"269\" height=\"187\" \/><\/a><\/h3>\n<p>When the product is scanned, the vertical black and white bars were converted in a decimal number, and this number was used as the product code. Because data is only encoded in 1 direction (across the bars) they are known as 1 dimensional barcodes, as opposed to newer QR codes, which are 2 dimensional barcodes.<\/p>\n<p>This meant that shops could accurately input the:<\/p>\n<ul>\n<li>Price of the product, meaning the sale price was correct<\/li>\n<li>The product ID, meaning that the sale could be automatically passed to the stock control database and stock levels could be updated automatically<\/li>\n<\/ul>\n<p>The human readable form of the barcode is printed below, in case the barcode scanner fails and the code needs to be entered manually.<\/p>\n<p>&nbsp;<\/p>\n\n<\/div><h2 class=\"tabtitle\">Barcodes<\/h2>\n<div class=\"tabcontent\">\n\n<h3>How 1 dimensional barcodes work<\/h3>\n<p>Barcodes are a machine readable form of data. They consist of a number of vertical black and white bars, into which the number is encoded. Below the barcode is the same number written in a human readable format, in case the data needs to be entered manually due to equipment failure.<\/p>\n<p>The most common form of 1 dimensional barcode is the Universal Product Code(UPC), this is the type of barcode found on most products in shops and online.<\/p>\n<p>The data is encoded in the following format:<\/p>\n<p><a href=\"https:\/\/learnlearn.uk\/igcsecs\/wp-content\/uploads\/sites\/23\/2022\/01\/UPC-Barcode-components.png\"><img decoding=\"async\" loading=\"lazy\" class=\"alignnone wp-image-452\" src=\"https:\/\/learnlearn.uk\/igcsecs\/wp-content\/uploads\/sites\/23\/2022\/01\/UPC-Barcode-components.png\" alt=\"\" width=\"756\" height=\"567\" srcset=\"https:\/\/learnlearn.uk\/igcsecs\/wp-content\/uploads\/sites\/23\/2022\/01\/UPC-Barcode-components.png 960w, https:\/\/learnlearn.uk\/igcsecs\/wp-content\/uploads\/sites\/23\/2022\/01\/UPC-Barcode-components-300x225.png 300w, https:\/\/learnlearn.uk\/igcsecs\/wp-content\/uploads\/sites\/23\/2022\/01\/UPC-Barcode-components-768x576.png 768w\" sizes=\"(max-width: 756px) 100vw, 756px\" \/><\/a><\/p>\n<p><strong>Guard Bars<\/strong><\/p>\n<p>These bars serve as a reference point for barcodes and are used by the scanner to determine the boundary of the barcode and the width of an individual line.<\/p>\n<p><strong>Number System Bars<\/strong><\/p>\n<p>These are normally used to represent the product type<\/p>\n<p><strong>Manufacturer ID 5 digits (0-9)<\/strong><\/p>\n<p>This represents the manufacturer ID. Because each manufacturer is issued a unique ID by the issuing authority, no two barcodes by different manufacturers should be the same.<\/p>\n<p><strong>Middle Bars<\/strong><\/p>\n<p>The middle bars are used as a reference point for scanners to determine if the barcode is upside down or the right way up.<\/p>\n<p><strong>Product ID 5 digits (0-9)<\/strong><\/p>\n<p>This represents the ID of the individual product from the manufacturer.<\/p>\n<p><strong>Modulo check bars<\/strong><\/p>\n<p>This contains the<a href=\"http:\/\/learnlearn.uk\/igcsecs\/error-detection\/\"> check digit<\/a>, used to check for automatic read errors. The human readable form below is also added to check for manual human input errors.<\/p>\n\n<\/div><h2 class=\"tabtitle\">Barcode Digits<\/h2>\n<div class=\"tabcontent\">\n\n<h3>How are the digits encoded?<\/h3>\n<p>UPC barcodes contain a total of 10 encoded digits, 5 on the left, 5 on the right.<\/p>\n<p><img decoding=\"async\" loading=\"lazy\" class=\" wp-image-474 alignnone\" src=\"https:\/\/learnlearn.uk\/igcsecs\/wp-content\/uploads\/sites\/23\/2022\/01\/left-vs-right-digits.jpg\" alt=\"\" width=\"447\" height=\"180\" srcset=\"https:\/\/learnlearn.uk\/igcsecs\/wp-content\/uploads\/sites\/23\/2022\/01\/left-vs-right-digits.jpg 554w, https:\/\/learnlearn.uk\/igcsecs\/wp-content\/uploads\/sites\/23\/2022\/01\/left-vs-right-digits-300x121.jpg 300w\" sizes=\"(max-width: 447px) 100vw, 447px\" \/><\/p>\n<p>&nbsp;<\/p>\n<p>Each digits is made up of 7 segments and the number of bars is always 2 black and 2 white, or varying thickness.<\/p>\n<div id=\"attachment_472\" style=\"width: 198px\" class=\"wp-caption alignnone\"><img aria-describedby=\"caption-attachment-472\" decoding=\"async\" loading=\"lazy\" class=\"wp-image-472 size-full\" src=\"https:\/\/learnlearn.uk\/igcsecs\/wp-content\/uploads\/sites\/23\/2022\/01\/number-1-7-segments-shown.png\" alt=\"\" width=\"188\" height=\"160\" \/><p id=\"caption-attachment-472\" class=\"wp-caption-text\">Notice how it is split into 7 segments?<\/p><\/div>\n<p>On the left hand digits the total number of segments used for black lines (out of the 7 max) is always an even number.<\/p>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"wp-image-455 alignnone\" src=\"https:\/\/learnlearn.uk\/igcsecs\/wp-content\/uploads\/sites\/23\/2022\/01\/left-digits.png\" alt=\"\" width=\"515\" height=\"247\" srcset=\"https:\/\/learnlearn.uk\/igcsecs\/wp-content\/uploads\/sites\/23\/2022\/01\/left-digits.png 971w, https:\/\/learnlearn.uk\/igcsecs\/wp-content\/uploads\/sites\/23\/2022\/01\/left-digits-300x144.png 300w, https:\/\/learnlearn.uk\/igcsecs\/wp-content\/uploads\/sites\/23\/2022\/01\/left-digits-768x369.png 768w\" sizes=\"(max-width: 515px) 100vw, 515px\" \/><\/p>\n<p>The right hand digits are the exact opposite in color, therefore they have odd parity,<\/p>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"alignleft wp-image-456\" src=\"https:\/\/learnlearn.uk\/igcsecs\/wp-content\/uploads\/sites\/23\/2022\/01\/right-digits.png\" alt=\"\" width=\"518\" height=\"242\" srcset=\"https:\/\/learnlearn.uk\/igcsecs\/wp-content\/uploads\/sites\/23\/2022\/01\/right-digits.png 973w, https:\/\/learnlearn.uk\/igcsecs\/wp-content\/uploads\/sites\/23\/2022\/01\/right-digits-300x140.png 300w, https:\/\/learnlearn.uk\/igcsecs\/wp-content\/uploads\/sites\/23\/2022\/01\/right-digits-768x359.png 768w\" sizes=\"(max-width: 518px) 100vw, 518px\" \/><\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>The right and left hand side digits are encoded exactly opposite.<\/p>\n<div id=\"attachment_457\" style=\"width: 731px\" class=\"wp-caption alignleft\"><img aria-describedby=\"caption-attachment-457\" decoding=\"async\" loading=\"lazy\" class=\"wp-image-457\" src=\"https:\/\/learnlearn.uk\/igcsecs\/wp-content\/uploads\/sites\/23\/2022\/01\/alternating.gif\" alt=\"\" width=\"721\" height=\"253\" \/><p id=\"caption-attachment-457\" class=\"wp-caption-text\">Note that the right hand digits are the exact opposite to the left hand digits<\/p><\/div>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n\n<\/div><h2 class=\"tabtitle\">Barcode Scanners<\/h2>\n<div class=\"tabcontent\">\n\n<h3>How barcode scanners work<\/h3>\n<p>Barcode scanners work by emitting a wide beam of infrared, visible or laser light.<\/p>\n<p><strong>Step 1 &#8211; Light is emitted from the barcode scanner<\/strong><\/p>\n<p>In the first step a beam of light is emitted from the scanner. Depending on the scanner used it can be infrared light, laser light or visible light. Most modern supermarket scanners use laser light, as it is highly effective.<\/p>\n<p><strong>Step 2 &#8211; The light is reflected back from the barcode<\/strong><\/p>\n<p>The light bounces back from the barcode. The dark sections of the barcode absorb more light and so less light is reflected back from the dark bar areas.<\/p>\n<p><strong>Step 3 &#8211; Mirrors direct the returned light onto the face of a Charge Couple Device.<\/strong><\/p>\n<p>Mirrors inside the scanner direct and focus the returning light onto the surface of a charge coupled device. The CCD contains an array of photosensitive cells, varying the electrical signal being passed by the CCD.<\/p>\n<p><strong>Step 4 &#8211; The analogue signal is converted to digital form.<\/strong><\/p>\n<p>An analogue to digital convertor (ADC) inside the reader converts the data from analogue electrical signals to digital form and checks that the barcode has been scanned correctly, through the use of the modulo bar data.<\/p>\n<p><strong>Step 5 &#8211; The scanner sends the barcode data to the computer.<\/strong><\/p>\n<p>Once the data has been converted and checked, the data is passed on to the computer. In a supermarket the computer is usually an Electronic Point Of Sale(EPOS) device, tailored to the needs of the supermarket.<\/p>\n\n<\/div><h2 class=\"tabtitle\">Pros &amp; Cons<\/h2>\n<div class=\"tabcontent\">\n\n<h3>Advantages &amp; Disadvantages of Barcode Readers<\/h3>\n<p><strong>Advantages<\/strong><\/p>\n<ul>\n<li>Stock levels can be updated automatically, making stock control easier<\/li>\n<li>Very cheap for each label, as it was just printed on the side of the product label<\/li>\n<\/ul>\n<p><strong>Disadvantages<\/strong><\/p>\n<ul>\n<li>Limitations on 2D barcodes mean that individual items can\u2019t be tracked, only product types.<\/li>\n<li>Doesn\u2019t help track the product for security purposes<\/li>\n<\/ul>\n\n<\/div><h2 class=\"tabtitle\">Quiz<\/h2>\n<div class=\"tabcontent\">\n\n<h3>Topic Review Quiz<\/h3>\n<p><iframe loading=\"lazy\" src=\"https:\/\/docs.google.com\/forms\/d\/e\/1FAIpQLScfvaJ8FLTTxZNMBYLOet0M-VyFcF_YudpTmahNY8zV6IFE3Q\/viewform?embedded=true\" width=\"900\" height=\"2973\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\">Loading\u2026<\/iframe><\/p>\n\n<\/div><h2 class=\"tabtitle\">Resources<\/h2>\n<div class=\"tabcontent\">\n\n<h3>Resources<\/h3>\n<p><strong>Python Programming Challenge<\/strong><\/p>\n<p>Write a python program that takes an 11 digit code and converts it to the correct sequence of black and white to be encoded on the barcode.<\/p>\n<p>Bonus challenge &#8211; Adapt your algorithm to <a href=\"http:\/\/learnlearn.uk\/igcsecs\/error-detection\/\">calculate the MOD 10 check digit<\/a> at the end of the barcode<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p><a href=\"https:\/\/pastpapers.papacambridge.com\/viewer\/caie\/cambridge-upper-secondary-igcse-computer-science-0478-2015-jun-0478-s15-qp-12-pdf\">0478\/12 Paper 1 Theory May\/June 2015 &#8211; Qn3<\/a><\/p>\n<p><a href=\"https:\/\/pastpapers.papacambridge.com\/viewer\/caie\/cambridge-upper-secondary-igcse-computer-science-0478-2016-jun-0478-s16-qp-12-pdf\">0478\/12 &#8211; Paper 1 Theory May\/June 2016 Qn 9<\/a><\/p>\n<p><a href=\"https:\/\/pastpapers.papacambridge.com\/viewer\/caie\/cambridge-upper-secondary-igcse-computer-science-0478-2017-jun-0478-s17-qp-11-pdf\">0478\/11 &#8211; Paper 1 Theory May\/June 2017 Qn 9<\/a><\/p>\n<p><a href=\"https:\/\/pastpapers.papacambridge.com\/viewer\/caie\/cambridge-upper-secondary-igcse-computer-science-0478-2018-march-0478-m18-qp-12-pdf\">0478\/12 Paper 1 Theory February\/March 2018 Qn11<\/a><\/p>\n<p><a href=\"https:\/\/pastpapers.papacambridge.com\/viewer\/caie\/cambridge-upper-secondary-igcse-computer-science-0478-2018-may-june-0478-s18-qp-11-pdf\">0478\/11 &#8211; Paper 1 Theory May\/June 2018\u00a0 Qn8<\/a><\/p>\n<\/div><\/div>\n","protected":false},"excerpt":{"rendered":"<p>Barcode Readers With the rapid growth of a consumer society in post-war America there grew a demand for technologies that would improve the efficiency of stock control and sales of goods. The first patent for barcodes was issued in 1951, for a circular barcode. Adapted from Morse code and using variable thickness rings it was&hellip;&nbsp;<a href=\"https:\/\/learnlearn.uk\/igcsecs\/barcode-scanners\/\" class=\"\" rel=\"bookmark\">Read More &raquo;<span class=\"screen-reader-text\">Barcode Scanners<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"neve_meta_sidebar":"","neve_meta_container":"","neve_meta_enable_content_width":"on","neve_meta_content_width":90,"neve_meta_title_alignment":"","neve_meta_author_avatar":"","neve_post_elements_order":"","neve_meta_disable_header":"","neve_meta_disable_footer":"","neve_meta_disable_title":""},"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v20.6 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>Barcode Scanners | IGCSE Computer Science | Learnlearn.uk<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/learnlearn.uk\/igcsecs\/barcode-scanners\/\" \/>\n<meta property=\"og:locale\" content=\"en_GB\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Barcode Scanners | IGCSE Computer Science | Learnlearn.uk\" \/>\n<meta property=\"og:description\" content=\"Barcode Readers With the rapid growth of a consumer society in post-war America there grew a demand for technologies that would improve the efficiency of stock control and sales of goods. The first patent for barcodes was issued in 1951, for a circular barcode. Adapted from Morse code and using variable thickness rings it was&hellip;&nbsp;Read More &raquo;Barcode Scanners\" \/>\n<meta property=\"og:url\" content=\"https:\/\/learnlearn.uk\/igcsecs\/barcode-scanners\/\" \/>\n<meta property=\"og:site_name\" content=\"IGCSE Computer Science\" \/>\n<meta property=\"article:modified_time\" content=\"2022-01-25T07:19:51+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/learnlearn.uk\/igcseict\/wp-content\/uploads\/sites\/3\/2016\/08\/barcode-scanner.png?_t=1618364933\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Estimated reading time\" \/>\n\t<meta name=\"twitter:data1\" content=\"5 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\/\/learnlearn.uk\/igcsecs\/barcode-scanners\/\",\"url\":\"https:\/\/learnlearn.uk\/igcsecs\/barcode-scanners\/\",\"name\":\"Barcode Scanners | IGCSE Computer Science | Learnlearn.uk\",\"isPartOf\":{\"@id\":\"https:\/\/learnlearn.uk\/igcsecs\/#website\"},\"datePublished\":\"2022-01-10T10:23:10+00:00\",\"dateModified\":\"2022-01-25T07:19:51+00:00\",\"breadcrumb\":{\"@id\":\"https:\/\/learnlearn.uk\/igcsecs\/barcode-scanners\/#breadcrumb\"},\"inLanguage\":\"en-GB\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/learnlearn.uk\/igcsecs\/barcode-scanners\/\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/learnlearn.uk\/igcsecs\/barcode-scanners\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"IGCSE Computer Science Course\",\"item\":\"https:\/\/learnlearn.uk\/igcsecs\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Barcode Scanners\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/learnlearn.uk\/igcsecs\/#website\",\"url\":\"https:\/\/learnlearn.uk\/igcsecs\/\",\"name\":\"IGCSE Computer Science\",\"description\":\"\",\"publisher\":{\"@id\":\"https:\/\/learnlearn.uk\/igcsecs\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/learnlearn.uk\/igcsecs\/?s={search_term_string}\"},\"query-input\":\"required name=search_term_string\"}],\"inLanguage\":\"en-GB\"},{\"@type\":\"Organization\",\"@id\":\"https:\/\/learnlearn.uk\/igcsecs\/#organization\",\"name\":\"IGCSE Computer Science\",\"url\":\"https:\/\/learnlearn.uk\/igcsecs\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-GB\",\"@id\":\"https:\/\/learnlearn.uk\/igcsecs\/#\/schema\/logo\/image\/\",\"url\":\"https:\/\/learnlearn.uk\/igcsecs\/wp-content\/uploads\/sites\/23\/2020\/08\/LearnLearnLogowhitenew.png\",\"contentUrl\":\"https:\/\/learnlearn.uk\/igcsecs\/wp-content\/uploads\/sites\/23\/2020\/08\/LearnLearnLogowhitenew.png\",\"width\":710,\"height\":98,\"caption\":\"IGCSE Computer Science\"},\"image\":{\"@id\":\"https:\/\/learnlearn.uk\/igcsecs\/#\/schema\/logo\/image\/\"}}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"Barcode Scanners | IGCSE Computer Science | Learnlearn.uk","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/learnlearn.uk\/igcsecs\/barcode-scanners\/","og_locale":"en_GB","og_type":"article","og_title":"Barcode Scanners | IGCSE Computer Science | Learnlearn.uk","og_description":"Barcode Readers With the rapid growth of a consumer society in post-war America there grew a demand for technologies that would improve the efficiency of stock control and sales of goods. The first patent for barcodes was issued in 1951, for a circular barcode. Adapted from Morse code and using variable thickness rings it was&hellip;&nbsp;Read More &raquo;Barcode Scanners","og_url":"https:\/\/learnlearn.uk\/igcsecs\/barcode-scanners\/","og_site_name":"IGCSE Computer Science","article_modified_time":"2022-01-25T07:19:51+00:00","og_image":[{"url":"https:\/\/learnlearn.uk\/igcseict\/wp-content\/uploads\/sites\/3\/2016\/08\/barcode-scanner.png?_t=1618364933"}],"twitter_card":"summary_large_image","twitter_misc":{"Estimated reading time":"5 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/learnlearn.uk\/igcsecs\/barcode-scanners\/","url":"https:\/\/learnlearn.uk\/igcsecs\/barcode-scanners\/","name":"Barcode Scanners | IGCSE Computer Science | Learnlearn.uk","isPartOf":{"@id":"https:\/\/learnlearn.uk\/igcsecs\/#website"},"datePublished":"2022-01-10T10:23:10+00:00","dateModified":"2022-01-25T07:19:51+00:00","breadcrumb":{"@id":"https:\/\/learnlearn.uk\/igcsecs\/barcode-scanners\/#breadcrumb"},"inLanguage":"en-GB","potentialAction":[{"@type":"ReadAction","target":["https:\/\/learnlearn.uk\/igcsecs\/barcode-scanners\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/learnlearn.uk\/igcsecs\/barcode-scanners\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"IGCSE Computer Science Course","item":"https:\/\/learnlearn.uk\/igcsecs\/"},{"@type":"ListItem","position":2,"name":"Barcode Scanners"}]},{"@type":"WebSite","@id":"https:\/\/learnlearn.uk\/igcsecs\/#website","url":"https:\/\/learnlearn.uk\/igcsecs\/","name":"IGCSE Computer Science","description":"","publisher":{"@id":"https:\/\/learnlearn.uk\/igcsecs\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/learnlearn.uk\/igcsecs\/?s={search_term_string}"},"query-input":"required name=search_term_string"}],"inLanguage":"en-GB"},{"@type":"Organization","@id":"https:\/\/learnlearn.uk\/igcsecs\/#organization","name":"IGCSE Computer Science","url":"https:\/\/learnlearn.uk\/igcsecs\/","logo":{"@type":"ImageObject","inLanguage":"en-GB","@id":"https:\/\/learnlearn.uk\/igcsecs\/#\/schema\/logo\/image\/","url":"https:\/\/learnlearn.uk\/igcsecs\/wp-content\/uploads\/sites\/23\/2020\/08\/LearnLearnLogowhitenew.png","contentUrl":"https:\/\/learnlearn.uk\/igcsecs\/wp-content\/uploads\/sites\/23\/2020\/08\/LearnLearnLogowhitenew.png","width":710,"height":98,"caption":"IGCSE Computer Science"},"image":{"@id":"https:\/\/learnlearn.uk\/igcsecs\/#\/schema\/logo\/image\/"}}]}},"rttpg_featured_image_url":null,"rttpg_author":{"display_name":"learnlearnadmin","author_link":"https:\/\/learnlearn.uk\/igcsecs\/author\/learnlearnadmin\/"},"rttpg_comment":0,"rttpg_category":null,"rttpg_excerpt":"Barcode Readers With the rapid growth of a consumer society in post-war America there grew a demand for technologies that would improve the efficiency of stock control and sales of goods. The first patent for barcodes was issued in 1951, for a circular barcode. Adapted from Morse code and using variable thickness rings it was&hellip;&nbsp;Read&hellip;","_links":{"self":[{"href":"https:\/\/learnlearn.uk\/igcsecs\/wp-json\/wp\/v2\/pages\/354"}],"collection":[{"href":"https:\/\/learnlearn.uk\/igcsecs\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/learnlearn.uk\/igcsecs\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/learnlearn.uk\/igcsecs\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/learnlearn.uk\/igcsecs\/wp-json\/wp\/v2\/comments?post=354"}],"version-history":[{"count":25,"href":"https:\/\/learnlearn.uk\/igcsecs\/wp-json\/wp\/v2\/pages\/354\/revisions"}],"predecessor-version":[{"id":805,"href":"https:\/\/learnlearn.uk\/igcsecs\/wp-json\/wp\/v2\/pages\/354\/revisions\/805"}],"wp:attachment":[{"href":"https:\/\/learnlearn.uk\/igcsecs\/wp-json\/wp\/v2\/media?parent=354"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}