1results about How to "Increase barcode density" patented technology

The invention discloses a four-unit bar and blank crossed bar code and an application method of the four-unit bar and blank crossed bar code, and aims at improving the one-dimensional bar code density. Particularly, a data character string width unit even parity check character is adopted, the error reading can be avoided, in addition, four groups of bar and blank crossed units of each pair of characters can express the states or the serial numbers of 256 questions, the bar code density is improved, when the four-unit bar and blank crossed bar code is used for selecting answer bar codes, the question serial number quantity requirement of normal answer sheets can be met through one pair of data, and when the length of a selected answer frame is not greater than eight, the length is marked by three units including a blank, a bar and a blank in front of a stop character, and the bar code length is further reduced; the selected answer bar codes can be used for various written selective answer sheet or questionnaire occasions, the answer frame full-filling information can be fast collected by a bar code gun, a mobile phone, a scanner or a cursor card reader, and the question serial number and the answer selection are recorded; the four-unit bar and blank crossed bar code and the method are particularly suitable for the fast paper reading by teachers, the exam results of students in each time are collected, recorded, counted and analyzed, and the full record in the whole life is realized.