Some standard content:
National Standard of the People's Republic of China
GB/T2683—1981
Fax Test Sample
Published on January 1, 1982
Implemented on January 1, 1982
General Administration of Standards of the People's Republic of China
1 Scope of Application
National Standard of the People's Republic of China
Fax Test Sample
GB/T2683—1981
This standard is mainly applicable to the performance and transmission quality of Class I and Class II authentic fax equipment. According to the degree of distortion of each pattern reproduced by the receiver, the corresponding technical parameters or indicators can be objectively or subjectively evaluated. It can also be used to conduct some tests on photo fax systems (except half-color characteristics) and other types of fax systems. 2 Contents of measurement and use of graphics
2.1 Format size and effective area*
The sample is printed in two formats: A4 (210mm×297mm) and B4 (186mm×263mm). The small solid circle on the vertical and horizontal size scales in the graphic is the B4 format mark, and the small hollow circle is the A4 format mark. The rectangle of 165mm×250mm formed by the four intersections of the scale lines is the standard effective area of the current second-class genuine fax machine in my country. There is a small triangle mark at the center of 165mm, and the effective area can be read using the scale.
*Effective area 1 is the product of the effective length of the scanning line and the maximum length of the message that can be transmitted. 2.2 Character readability
It consists of 210 Chinese characters in size 4 Fangsong style. The first 200 characters are arranged from left to right and from top to bottom according to the complexity of the strokes, and are used for readability testing. The last group (lower right corner) has 5 pairs of characters with similar shapes that are easily confused. They are used as a reference. Graphics
Review) Notes
Graphics
60 size 4 (13.75P) Fangsong Chinese characters, the direction of the characters is 90° to the character in the middle 32 size 5 (10.5P) Fangsong Chinese characters, 4 characters in a group, arranged in two directions at 90° to each other. There are also (size 5 font for reference) Latin letters, Arabic numerals and punctuation marks in 12P isolinear font with white and black backgrounds. Handwritten Chinese characters and Mongolian, Tibetan, Uyghur, Korean and Kazakh characters. Graphics with black and white backgrounds, bold fonts, the name of this sample and the note column. Readability (%) The number of recognizable characters (excluding the last 10) divided by 200. The various characters and symbols between the last 5 pairs of characters above are all used as references for evaluation. 2.3 Resolution
2.3.1 The following graphics are used to determine the main scanning resolution: Graphics
5 groups of identical black and white lines, the thin line width is 0.25mm, and the interval between black and white is 4mm. 5 groups of black and white lines. The width of each group of thin lines is 0.40, 0.33, 0.25, 0.23, 0.20 respectively. mm, the black and white spacing in the middle of the line group is 3mm. The black spacing on the left and right sides of groups 1 to 5 are 3.9, 4.355, 4.875 and 5.2mm respectively. Graphics·
Graphics:
Graphics·
A group of 27 black and white wedge-shaped lines, with a total length of 47mm, and the scales next to them indicate the line width in millimeters. The scale lines for each black and white background are marked with line widths in millimeters. Black and white lines of equal width, line width is 0.5mm. Black and white lines of equal width, line width is 0.25mm. Equally spaced white lines with a black background, white line width is 0.25mm. Black spacing is 4.75mm. Equally spaced black lines with a white background, black line width is 0.25mm. White spacing is 9.75mm. Read the above picture of the received copy The width of the line that can be reproduced in the type is 1 (mm), then the value of the main scanning resolution is 1/. Issued by the General Administration of Graphics National Standards
Proposed by the Ministry of Posts and Telecommunications of the People's Republic of China
Implementation on January 1, 1982
Drafted by the Institute of Telecommunications Transmission of the Ministry of Posts and Telecommunications
Used to check the resolution of isolated lines.
2.3.2 Sub-scanning resolution:
GB/T2683—1981
Horizontal V-shaped line, 100mm long, 0.25mm wide, and 3mm V-shaped opening. The value of the sub-scanning resolution of the transmitter is the number of times the scanning line segments contained in the V-shaped line are connected divided by 3 (mm). 2.4 Synchronization error
Vertical and horizontal dimension scale lines in millimeters . When the synchronization error is large, all rectangular patterns in the sample receiving copy will become diamonds, and circles will become oblique ellipses. To quantitatively measure the synchronization error, transparent coordinate paper can be used to make its horizontal axis coincide with the horizontal scale line on the upper part of the sample receiving copy, and the intersection of this horizontal scale line and the right vertical scale line is taken as the coordinate origin. The distance from 100mm on the vertical axis of the transparent coordinate paper to the right vertical scale line of the sample receiving copy is the slope value, and the double slope value can also be read at 200mm. 2.5 In-phase error The small triangle on the horizontal scale line in the
pattern marks the center position of the effective length of the scanning line. When the initial phases between the sending and receiving devices are inconsistent, the small triangle mark on the sample receiving copy is asymmetrical to the two sides of the effective length of the scanning line. When measuring, make the distances from the four intersections of the pattern ·
on the sample original to the pressure strip of the sending roller equal. If the transmitter is a flat type, align the triangle mark of the pattern · with the middle position of the effective length of the scanning line. At the receiving end, mark the center of the effective length of the scanning line on the recording paper. If this center position does not coincide with the recorded small triangle, it means that the initial phase between the two ends of the transmitter and receiver is inconsistent, and the error value can be read on the scale line. 2.6 Cooperation Index
The four concentric circles of the graph have radii of 20.5, 14, 9.5.6.75mm respectively. The line widths are 1.5, 1, 0.5, and 0.25mm respectively. The 45° oblique line through the center of the circle has a line width of 0.2mm. When the cooperation index of the receiving and transmitting equipment is inconsistent, the concentric circles of the graph are flattened in the axial direction to become an ellipse. If the major axis of the ellipse is in the horizontal direction, it means that the cooperation index of the receiver is greater than that of the transmitter. If the major axis of the ellipse is in the vertical direction, it means that the cooperation index of the receiver is less than that of the transmitter. Quantitative measurement can be measured with a standard ruler to measure the degree of deformation of the size of the graph recorded by the receiving copy. 2.7 Scanning uniformity
Measure the jitter in the main scanning direction using a pattern. The pattern consists of 5 vertical straight lines, 250mm long, 0.25mm wide, and 1.75mm apart. When there is jitter, some lines in the pattern appear wavy. Make an average line through most of the recording points. Then measure the distance from the recording point that deviates the most from the average line to the average line, which is the jitter value. 2.8 Black and white adjustment
The pattern consists of five levels of optical density composed of 120 pairs of dots per inch, 9, 7, 5, and 3.1 dots respectively. The pattern can check the analog response of the scanner to limited intermediate tones, and can be used together with the pattern... to determine whether the black and white threshold level is appropriate. 2.9 Transmission distortion and interference
The distortion of the transmission signal after passing through the transmission path is manifested as ghosting of the image, blurred outlines, or thickening or thinning of lines. Various interferences are manifested on the received copy as dots, lines, or image interruptions that are not in the original. 2.10 OthersbzxZ.net
Black horizontal wedge line, 186mm long, 8mm wide, the slope starts at 139.5mm. At the beginning of the slope, there is a white line with a width of 0.3mm and a height of 3mm. Pattern: used to check the image tailing in synchronous detection mode. Pattern
3 Printing requirements
3.1 Paper
Equal width black and white lines, line width is 5mm. Mainly used to observe the influence of group delay distortion. Use coated paper and wood-based paper.
Weight: 100g/m2±15g/m2
Thickness: 0.8~1.2mm
Dimensional accuracy
GB/T2683—1981
The geometrical dimension error of the main pattern should be: nominal dimension ± (1% ± 0.01) mm. Density
Ink density is above 1.5, and reflection coefficient is below 3%.
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.