1、BRITISH STANDARD Methods of Measurement on receivers for television broadcast transmissions Part 7. HDTV displays The European Standard EN 60107-7 : 1997 has the status of a British Standard ICs 33.160.20 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BS EN 60107-7 : 1997 IEC
2、 60107-7 : 1997 STD.BS1 BS EN bOLO7-7-ENGL 1997 Lb24bb9 0b243b3 807 Amd. No. BS EN 60107-7 : 1997 Date Text affect - present to the responsible internaionaM3uropean committee any enquiries on the interpretation, or proposais for change, and keep the UK interests informed; - monitor related internati
3、onal and European developments and promulgate them in the UK. A list of organizations represented on this subcommittee cm be obtained on request to its secretary. Cross-references Attention is drawn to the fact that annex ZA iists normative references to international publications with their corresp
4、onding European publications. The British Standards which implement these international or European publications may be found in the BSI Standards Catalogue under the section entitled International Stan - relative humidity: 25 Yo to 75 Yo; - air pressure: 86 kPa to 106 kPa. If the manufacturer finds
5、 it necessary to specify climatic conditions differing from the above, these should be chosen from IEC 68-1 and the measurements shall be made under these specified conditions. The conditions mentioned above represent those under which the equipment is required to meet its specifications. Over a wid
6、er range, the equipment may operate but not meet all of its specifications and it may be permissible to store the equipment under much more extreme conditions. For more complete discussion of these concepts, reference should be made to IEC 68. 2.1.4 Precautions during measurement When carrying out m
7、easurements, all test conditions or operations which may lead to damage of the display shall be avoided. This applies particularly to sensitive, solid-state devices and similar constructions. If a protective cover is removed and parts that are directly connected to the mains become accessible, the e
8、quipment shall be connected to the a.c. mains via a safety transformer, the secondary winding of which is insulated in accordance with the principle of double insulation. It shall be ascertained that the use of a safety transformer does not influence the receiver properties to be measured. In partic
9、ular, the internal impedance of the safety transformer shall be sufficiently low for the behaviour of the display to be the same as when directly connected to the mains supply. 2.1.5 Power supply Measurements of the display characteristics shall be carried out at the rated voltage of the power suppl
10、y. The fluctuation of the power supply voltage during the tests shall not exceed *2 %. When a.c. mains are used, the frequency fluctuation and the harmonic components of the power supply shall not exceed 12 % and 5 % respectively. To determine the influence of variations in the supply voltages on th
11、e display characteristics, supplementary measurements may be needed at overvoltages and undervoltages, these being chosen appropriately with due regard to the manufacturers specifications. STD-BSI BS EN bO107-7-ENGL 1777 m 1b24bb7 Ob24371 783 m Page 8 EN 60107-7 : 1997 2.1.6 Stabilization period In
12、order to ensure that when measurement begins, characteristics do not change significantly with time, the display shall be operated under standard measuring conditions for a sufficient period to permit the characteristics to stabilize. 2.1.7 Test room Measurements shall be carried out in a room that
13、is not subject to disturbing external interference from electromagnetic fields. If interference may effect the results, the measure- ments shall be carried out in a screened room. 2.2 Input signals 2.2.1 Video signals Input video signals to the display shall be YPBPR component signals where Y is the
14、 luminance signal; PB is the B-Y signal; PR is the R-Y signal. The synchronizing signal shall be a composite sync signal consisting of tri-level, bipolar line synchronizing pulses and field synchronizing pulses. The Y signal shall be accompanied by the synchronizing signal. Some displays may require
15、 R, G, and B signals instead of the YPBPR component signals. Such displays require that the synchronizing signal or line and field driving pulses be separate. NOTE - Some displays can be operated by negative synchronizing pulses. 2.3 Test signals 2.3.1 Video test signals (general remarks) Waveforms
16、of test signals and test patterns shown in this clause are examples; however, other signals with similar characteristics may also be used. The amplitude of a picture component is measured from the blanking level and expressed as a percentage to the amplitude of the reference white level. The black l
17、evel coincides with the blanking level. The white reference level can be obtained from the Y signals for composite test patterns, colour bars and staircase signals, which are defined in this subclause. NOTE - In order to avoid excessive overshoots of the signal waveform which may occur in the displa
18、y under test, high-frequency components of the video signal beyond the nominal frequency bandwidth of the system should be attenuated by suitable low-pass filters. STD-BSI BS EN bOL07-7-ENGL L777 Lb24bbS Ob24372 BIT Page 9 EN 60107-7 : 1997 2.3.1.1 Composite test pattern signal A composite test patt
19、ern signal comprises a combination of monochrome and colour signal components that offer as much information as possible on the performance of the displays. Such a pattern should include at least the following items: - circles and equidistant horizontal and vertical lines for linearity and colour co
20、nvergence checks; - a marking to check the visible picture size (see 4.1.3); - a known brightness scale comprising 5 to 10 brightness steps for gradation checks; - vertical and horizontal definition wedges in the centre and in the four corners of the picture area; - vertical bars of different widths
21、 or a wedge and horizontal blocks giving black-white and white-black transitions for checking overshoot, reflections and low-frequency response; - areas at the reference white level and black level to check the maximum and minimum brightness of the picture; - coloured areas to check decoding operati
22、on, colour transitions and luminance/- chrominance time equalization. An average picture level (APL) of the pattern signal should be approximately 50 %. 2.3.1.2 Colour bar signal A colour bar signal consists of vertical bands of colours in order of descending luminance, left to right, as defined in
23、Recommendation ITU-R BT.471-1. For the measurements of the display, a 100 % colour bar signal consisting of (lOO/O/lOO/O) bars shall be used (for the nomenclature of bars, refer to ITU-R BT.471-1). R, G and B primary bar signals are shown in figure 1. Y, PB and PR bar signals shall comply with the H
24、DTV standard used. Waveforms of the signals are shown in figure 2. 2.3.1.3 Black and white cross-hatch pattern signals The white cross-hatch pattern signal produces a white cross-hatch on a black background and the black cross-hatch pattern signal produces a black cross-hatch on a white background.
25、The white cross-hatch pattern is used to measure convergence errors or registration errors of displays, and the black cross-hatch pattern is used as a scale for locating a point on the screen and other purposes. The cross-hatch pattern consists of equidistant horizontal and vertical lines which form
26、 rectangular windows. The screen has 13 and 21 lines, respectively, as shown in figure 3. These patterns require Y signal only. 2.3.1.4 Full white and full black signals The full white and full black signals are flat level Y signals whose amplitudes are set at 100 % and O % as shown in figure 4. The
27、se signals are used to measure luminance and other characteristics of a display. STD-BSI BS EN bOL07-7-ENGL 1977 1b2LIbbS Ob29373 75b E Page 10 EN 60107-7 1997 2.3.1.5 White window signal The white window signal is a Y signal which produces a white rectangular window on a black background as shown i
28、n figure 5. The width of the window is half the picture height. The signal amplitude of the window is variable from 1 O % to 1 O0 %. This signal is used to measure luminance of a display. 2.3.1.6 Black and white window signal The black and white window signal is a Y signal which produces a white rec
29、tangular window and four black rectangular windows on the 50 % grey background as shown in figure 6. The size of the windows is 2/15th of the picture height. This signal is used to measure contrast of a display. NOTE - This signal is adopted by the ITU-R Recommendation BT.815-1 4. Detailed parameter
30、s of the signal are described in this Recommendation. 2.3.1.7 Line and window signal The line and window signal is a Y signal which consists of two vertical white lines placed at the left and right sides of the picture and a window placed at the centre as shown in figure 7. The background is set at
31、black level. This signal is used to measure local picture distortion due to variation of the CRT beam current. 2.3.1.8 Composite sine-wave signal The composite sine-wave signal consists of a variable-frequency sine-wave component superimposed on a 50 Yo Y level with a peak-to-peak amplitude of 40 %
32、as shown in figure 8. The frequency of the sine-wave is variable from 100 kHz to 30 MHz. This signal is mainly used to measure amplitude-frequency response of the luminance channel. 2.3.1.9 Multiburst signal The multiburst signal comprises a white reference pulse and seven bursts of discrete frequen
33、cies from 1 MHz to 30 MHz. The frequency bursts having a peak-to-peak value of 40 YO are superimposed on a 50 % Y level. Its waveform is shown in figure 9. This signal is used to measure amplitude-frequency response of the luminance channel. 2.3.1 .10 2Tpulse and bar signal The pulse and bar signal
34、is composed of a sine-squared pulse and a sine-squared bar on the same line. The pulse width at the half amplitude and the rise time of the bar are equal to 2T: 1 2T = - fv where fv is the nominal frequency bandwidth of the video signal; 2T= 33 ns for a 30 MHz bandwidth. Page 11 EN 60107-7 : 1997 Du
35、ration of the bar is 36/128 H when measured at its half amplitude (H equals the line scan period). A line-time waveform of the signal is shown in figure 10. This signal is used to measure linear waveform response of the video channel. 2.3.1 .l 1 The horizontal bar signal is a Y signal which produces
36、 a horizontal white bar, whose width is equal to one half of the picture height, on the black background as shown in figure 11. Horizontal bar signal This signal is used to measure low-frequency square-wave response of the video channel. 2.3.1.1 2 Staircase signal and APL-variable staircase signal G
37、enerally a Staircase signal with a five-riser is used as the test signal. A line-time waveform of the five-riser signal is shown in figure 12a. The APL-variable staircase signal is composed of the staircase signal of one line and flat level signals of four lines. The average picture level of the tot
38、al signal can be adjusted in a range of 10 YO to 90 % by varying the amplitude of the flat level signals from O % to 100 %. A waveform of the signal is shown in figure 12b. These signals are used to measure line-time non-linearity of the video channel. 2.3.1.13 PLGEsignal The signal arranges narrow
39、black horizontal stripes on the left-hand side, two black stripes on the right-hand side and a white window on the black background as shown in figure 13. The levels of the left and right stripes are alternately set at 11 and 21 measured with an eight bit quantizing level, while the levels of the wh
40、ite and black correspond to 235 and 16, respectively. This signal is used to set the black level and to measure the peak white level. NOTE - This signai is adopted by the ITU-R as Recommendation BT.814-1 151. Detailed parameters of the signal are described in this Recommendation. The acronym, PLUGE,
41、 is derived from “Picture Line-up Generating Equipment“. 2.3.1.14 Checkered pattern signal The checkered pattern comprises checkered patterns on the left and right sides and a vertical line in the middle as shown in figure 14. The background of the pattern is set at a 25 % level. The checker consist
42、s of black and white square blocks with a width of one ninth of the picture height. This pattern is used to test the pulling on whites. 2.3.2 Audio test signals a) 1 kHz sine-wave signal b) Frequency-variable sine-wave signal The sine-wave signal operates in a frequency range of 50 Hz to 15 kHz. 2.4
43、 Test instruments 2.4.1 Video test signal generator The video test signal generator shall be capable of generating the test signals specified in 2.3.1 in the form of YPBPR component signals of the system for which the display under test is designed. Measurements of the colour difference channel requ
44、ire the test signal with a single colour component (R, G or B). Measurements of the synchronizing range require a test generator with variable line and field frequencies. 2.4.2 Audio test signal generator The audio test signal generator shall be capable of generating the test signals Specified in 2.
45、3.2 with an output level of 0,5 V r.m.s. across 47 kR. 2.4.3 Oscilloscope A conventional oscilloscope covering the video frequency range can be used. It is, however, necessary to prepare a very low capacitance probe when measuring the characteristics of the video channel at the CRT electrodes. 2.4.4
46、 Luminance meter and colorimeter The luminance meter (photometer) shall be capable of measuring the luminance of a small area on the screen within a range of 0,2 cd/m2 to about 1 O00 cd/m2. The colorimeter shall be capable of measuring the chromaticity of a small area on the screen as chromaticity c
47、o-ordinates (x,y) or (u,t) at a luminance level lower than 2 cd/m2. For precise measurement of the chromaticity co-ordinates, a colorimeter of spectrometer type is required. The area should be a circle with a diameter less than 4 % of the screen width. When measuring projection type displays and LCD
48、 displays, the luminance and chromaticity are measured at a location away from the screen. For this purpose, meters with a telescopic lens are required. 2.4.5 Other optical measuring instruments A sliding gauge or a cathetometer is required for measuring geometric distortion of the picture. When mea
49、suring viewing angles of projection and LCD displays, it is necessary to set the luminance meter on a stand with the scales of azimuth and elevation angles. When measuring a screen gain of a projector, an illuminance meter may be required. 2.4.6 Measurement set-up A notional block diagram of the measurement set-up is shown in figure 15. 2.5 Standard measuring conditions Unless otherwise specified, the conditions described in this subclause shall be applied. Page 13 EN 60107-7 : 1997 2.5.1 Standard input signal levels The input voltage of each video signal shall comprise the following v
