1、- STDaBSI BS EN 61041-5-ENGL 1998 D 1b24bb9 Ob92498 52T BRITISH STANDARD Methods of measurement Non-broadcast video -tape recorders Part 5. High-band video tape recorders, including those equipped with Y/C video connectors (NTSC/PAL) * VI * The European Standard EN 61041-5 : 1997 has the status of a
2、 British Standard ICs 33.160.40 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BS EN BS 7434 : Part 5 : 1998 IEC 61041-5 : 1997 61041-5 : 1998 STD-BSI BS EN b1041-5-ENGL 1998 1624669 0692499 4bb BS EN 61041-5 : 1998 Amd. No. National foreword Date Text affected This British S
3、tandard is the English language version of EN 61041-5 : 1997. It is identical with IEC 61041-5 : 1997. The K participation in its preparation was entrusted by Technical Committee EPU100, Audio,video and multimedia systems and equipment, to Subcommittee EPU100/2, Recording, which has the responsibili
4、ty to: - aid enquirers to understand the text; - present to the responsible internationalEuropean committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; - monitor related international and European developments and promulgate them in the UK This B
5、ritish Standard, having been prepared under the direction of the Eie therefore, these methods apply to measurement of the signal around those frequencies. 1.4.5 waveform distortion in vertical direction of a picture screen: Picture distortion in vertical direction of a picture screen caused by horiz
6、ontal (line) correlation process with a comb filter. It is measured as waveform distortion of luminance signal. 1.4.6 colour flicker: Flicker resulting from amplitude and phase variations of the chrominance signal from field to field. 1.4.7 colour change points: Transition points where the hue and/o
7、r level of the chrominance signal changes in the horizontal direction of a picture screen. 1.4.8 colour displacement in vertical direction: Time delay of the chrominance signal with respect to the luminance signal. It is measured as the number of horizontal lines. 1.4.9 colour distortion in vertical
8、 direction: Rise and fall time periods of the chrominance signal in the vertical direction. It is measured as the number of horizontal lines. 1.4.1 O Y signal: Abbreviated expression for luminance signal. 1.4.1 1 C signal: Abbreviation for chrominance signal. It is the colour subcarrier of the NTSC
9、or PAL system modulated by the chrominance signal. Section 2: Video characteristics, luminance signal (NTSWPAL) 2.1 Luminance signal-to-noise ratio This is the ratio of the reference voltage level (100 % level is 0,714 Vp-p for NTSC and 0,700 Vp-p for PAL) of the video test signal, with respect to t
10、he r.m.s. voltage level of noise at a flat part of the waveform of the luminance signal. 2.1.1 Test signal The test signal shall be as follows: a) for composite video input connector, see figure 1 ; b) for S video input connector, see figures 2 and 3. 2.1.2 Block diagram The block diagram for measur
11、ement shall be as follows: a) for composite video input connector, see figure 4; b) for S video input connector, see figure 5. STDeESI ES EN bL041-5-ENGL 5998 m Lb24669 Ob92509 135 m Page 10 EN 61041-6 : 1997 LPF sc trap Weight 2.1.3 Measurement 6 MHz 6 MHz On off off off - For a video tape recorder
12、 equipped with a composite video connector, the composite video test signal shall be as shown in figure 1. For a video tape recorder equipped with an S video connector, the S luminance and S chrominance test signals shall be as shown in figures 2 and 3. Then, using a colour noise meter, measure the
13、signal-to-noise ratio of the luminance signal. The following table lists the setting for the colour noise meter. a) Set the colour noise meter as follows: Table 1 - Setting of colour noise meter 1 I mmsitevideo sianai I S video sional I I HPF I 100 kHz I 100 kHz I b) Adjust the input level to 0,357
14、V for NTSC; 0,350 V for PAL. c) Read the colour noise meter. 2.1.4 Presentation of the results Presentation of the results shall be as follows: - the composite video connector: dB - the S video connector: dB 2.2 Horizontal resolution This is the resolution in the horizontal direction of a picture sc
15、reen. Toobtain the resolution, refer to the frequency where the test signal decreases a specified amount by recording and reproducing the resolution test signal of the luminance signal. 2.2.1 Test signal The test signal shall be a frequency sweep signal (synchronized with vertical sync signal) with
16、markers. The range or the frequency sweep shall be 100 kHz to 8 MHt. a) For composite video input connector, see figure 6. b) For S video input connector: - S luminance signal: use only the luminance portion of the test signal shown in figure 6; - S chrominance signal: use only the colour burst of t
17、he test signal shown in figure 6. 2.2.2 Block diagram The block diagram for measurement shall be as follows: a) for composite video input connector, see figure 7; b) for S video input connector, see figure 8. * * IB STD.BSI BS EN bL041-5-ENGL 1996 Lb24669 Ob925LO 957 Page 11 EN 61041-5 : 1997 2.2.3
18、Measurement Record and reproduce the frequency sweep test signal and read the frequency where the output level is 28,6 mV for NTSC; 28,O mV for PAL, which is -20 dB with respect to 40 % level. Use the following equation to obtain the horizontal resolution: Resolution s W x 2(1- a) f, / f, = 80 x f,
19、(TV line) where f, is the horizontal scanning frequency (MHz); a is the ratio of the blanking period in the horizontal scanning period (0,1700 for NTSC, 0,1875 for PAL); fo is the frequency (MHz) where the output signal level is 28,6 mV for NTSC; 28,O mV for PAL. NOTE - If the output signal contains
20、 too much noise and its level cannot be read clearly, apply single frequencies from within the normal sweep signal, one after another. Then, find the frequency at which the signal level reads 28,6 mV for NTSC or 28,O mV for PAL. 2.2.4 Presentation of results Presentation of the results shall be as f
21、ollows: - for the composite video signal: TV lines - for the S video signal: TV lines 2.3 Vertically correlated waveform distortion (waveform distortion of vertical This is to be measured as reproducibility of the waveform of vertical pulses when recording and reproducing the test signal for wavefor
22、m distortion measurement. luminance signal) 2.3.1 Test signal The test signal shall be as follows: a) for composite video input connector, see figure 9; b) for S video input connector: - S luminance signal: use only the luminance portion of the test signal shown in figure 9; - S chrominance signal:
23、use only the colour burst signal of the test signal shown in figure 9. NOTE - A window signal can be substituted for measurement of overshoot, pre-shoot, smear, and rise and fall time periods. 2.3.2 Block diagram The block diagram for measurement shall be as follows: a) for composite video input con
24、nector, see figure 7; b) for S video input connector, see figure 8. - STD.BSI BS EN 61041-5-ENGL 1998 Lb24669 0692511 893 Page 12 EN 61041-6 : 1997 Overshoot 2.3.3 Measurement Record and reproduce the test signal, and observe the output signal following items shall be measured. See figures 10, 11, 1
25、2, 13, and 14. a) Overshoot b) Pre-shoot c) Smear d) Rise and fall times e) Reproducibility of 1 H/2H/3H pulses Composite S video connector video connector % % 2.3.4 Presentation of results Smear Rise time Fall time Presentation of the results shall be as follows: Yo % H H H H Waveform distortion of
26、 luminance signal (vertical pulses) Rise pulse % Reproducibility of 1 H pulse Reproducibility of 2H puise % Reproducibility of 3H pulse % on an oscilloscope. The Fall pulse Rise pulse Fall pulse Yo % % % % % % % % I Pre-stmt I % I % I NOTE - All indications of the percentage values shall be with 0,l
27、 % resolution. I 2.4 Diagonal resolution This is the resolution in the diagonal direction 28,O mV for PAL, which is -20 dB of 40 % level, in a horizontal scanning period, and measured at the reference level video output connector) by the square root of 2. 2.4.1 Test signal The test signal shall be a
28、 diagonal resolution test signal of 145“ with respect to the horizontal direction as shown in figure 15 (the bottom half of the screen shows a circular zone plate signal as a sample signal). The signal shall contain colour burst and its level shall be 40 %. Numbers in the screen indicate horizontal
29、resolution h (x 100 TV lines). 2.4.2 Block diagram The block diagram for measurement shall be as follows: a) for composite video input connector, see figure 7; b) for S video input connector, see figure 8. * * m STD.BSI BS EN bLO41-5-ENGL 1998 m 1624669 0692512 72T m Page 13 EN 61041-5 : 1997 2.4.3
30、Measurement Record and reproduce the test signal shown in figure 15. Using the oscilloscope, observe the S luminance output signal which corresponds to the line selected for measurement shown also in figure 15. Figure 16 shows the waveform to be observed. If a comb filter is used in the Y signal pro
31、cessing circuitry, a dip can be seen around an area of 290 TV lines for NTSC; 330 TV lines for PAL. By referring to the waveforms shown in figures 16 and 17, read the resolution Rh where the level of the output signal is 28,6 mV for NTSC; 28,O mV for PAL, which is -20 dB of 40 YO level. Use the foll
32、owing equation to obtain diagonal resolution R,. 2.4.4 Presentation of results Presentation of the results shall be as follows: - for composite video input TV lines - for S video input TV lines 2.5 This is the ratio of the levels of the luminance signal at three frequencies: fsc (chrominance subcarr
33、ier frequency) and i500 kHz of fsc, with respect to the reference level of the test signal. This is to measure the frequency characteristics of the comb filter in a two-dimensional frequency domain. Frequency characteristics of diagonal resolution (i) (frequency response in two-dimensional frequency
34、 domain) 2.5.1 Test signal The test signal shali be a frequency sweep signal whose pattern is about 149“ for NTSC; 167“ for PAL (this signal results in 1/2 line offset at fsc) with respect to the horizontal direction shown in figure 18. The test signal shall contain a colour burst signal, and the le
35、vel of the sweep test signal shall be 40 %. The markers on the screen show frequencies of the test signal in a horizontal sweep period. 2.5.2 Block diagram See figure 7 for the block diagram for measurement. 2.5.3 Measurement The following steps show the procedure for measurement. a) Apply the test
36、signal to the composite video input connector (the test signal shall pass through a comb filter) and then record and reproduce the test signal. b) Apply the S luminance output signal to the oscilloscope, and select a horizontal time period of the test signal shown in figure 18, and observe the wavef
37、orm as shown in figure 19. c) The waveform of only the right half shall be measured. Frequency characteristics for NTSC Pi = 20 lg (100/40) x (Vi / Vs) f2 = 20 lg (i 00/40) x (V2/ Vs) P3 = 20 Ig ( 100/40) x ( V3/ VS) STDWBSI BS EN bL041-5-ENGL I1998 Lb24bb9 Ob92513 bbb D Page 14 EN 61041-6 : 1997 Fr
38、equency characteristics for PAL Pi = 20 Ig (70/30) x (Vi / Vs) f2 = 20 lg (70/30) x (V2/ Vs) f3 = 20 lg (70/30) x (V3/ Vs) where VS is the Luminance white level (0,714 V for NTSC; 0,700 V for PAL). 2.5.4 Presentation of results Presentation of the results shall be as follows: For NTSC fi (3,08 MHz)
39、dB P2 (3,58 MHz) dB P3 (4,08 MHz) dB For PAL Pl ($93 MHz) dB P2 (4,43 MHz) dB P3 (4,93 MHz) dB 2.6 This is the ratio of the video output levels of the luminance signal at the S video output connector, with respect to the reference level of the test signal. It can be measured by recording and reprodu
40、cing the multiburst test signal of a slanting pattern. Frequency characteristics of diagonal resolution (i) (frequency response in Y/C separation system) 2.6.1 Test signal The test signal shall be a multiburst signal of a slanting pattern. See figure 20. 2.6.2 Block diagram See figure 7 for the bloc
41、k diagram for measurement. 2.6.3 Measurement Record and reproduce the test signal, and observe each level of the multiburst obtained at the S luminance output connector. Use the following equation to calculate the frequency characteristics. See figure 21. II . Frequency characteristic of the slantin
42、g pattern for NTSC is: 20 Ig (100/40) x (Vy/Vs) dB Frequency characteristic of the slanting pattern for PAL is: 20 Ig (70/30) x (Vy/ Vs) 2.6.4 Presentation of results dB Presentation of the results shall be as follows: For NTSC 49“ at 3,58 MHz dB 38“ at 3,58 MHt dB 67“ at 338 MHz dB 45“ at 3,08 MHz
43、dB 53“ at 4,08 MHz dB For PAL 67“ at 4,43 MHz dB 50“ at 4,43 MHz dB 90“ at 4,43 MHz dB 65“ at 3,93 MHz dB 70“ at 4,93 MHz dB Section 3: Video characteristics, chrominance signal (NTSWPAL) 3.1 Signal-to-noise ratio This is the ratio of the reference voltage level (where 100 % level is 714,O milpvp fo
44、r NTSC; 700,O m Vp-p for PAL) of the video signal, with respect to the r.m.s. voltage levels of the AM and PM noise remaining in the chrominance signal. 3.1.1 Test signal The test signal for measurement shall be as follows: a) for composite video input connector, see figure 22; b) for S video input
45、connector, see figures 23 and 24. 3.1.2 Block diagram The block diagram for measurement shall be as follows: a) for composite video input connector, see figure 25; b) for S video input connector, see figure 26. 3.1.3 Measurement Record and reproduce the test signal. Apply the signal from the composi
46、te video output connector or the S video output connector to the colour noise meter. The ranges of the noise meter shall be set as follows: HPF: 100 Hz LPF: 500kHz Hue compensation: on (for NTSC only. Set to an optimum position) Set the level of the input signal to 0,628 V for NTSC; 0,660 V for PAL,
47、 and read the AM and PM noise on the colour noise meter. 3.1.4 Presentation of the results Presentation of the results shall be as follows: Signal-to-noise ratio of AM colour dB Signal-to-noise ratio of PM colour dB Signal-to-noise ratio of AM colour dB Signal-to-noise ratio of PM colour dB - for co
48、mposite video signal - for S video signal 3.2 Vertical picture displacement This is the time delay between the chrominance signal and the luminance signal measured in the vertical direction of a picture screen. This can be obtained practically by the number of scanning lines, using a colour window t
49、est signal. 3.2.1 Test signal The test signal shall be as follows: a) for composite video input connector, see figure 27; b) for S video input connector, see figures 28 and 29. STD.BS1 ES EN bLO41-5-ENGL 1998 lb24bb9 Ob92515 439 Page 16 EN 61041-6 : 1997 The signal is a colour window signal. The level of the chrominance signal in the window shall be 100 %, and phase of the colour signal shall be in phase with the colour burst. The level of the luminance signal in the window shall be 50 %. 3.2.2 Block diagram The block diagram for measurement shall be as fo
