The Basics of Monitor Technology (1)

Transcription

1 The Basics of Monitor Technoogy (1)

2 Preface In recent years, the editing systems and equipment used by broadcasters, production houses and independent studios have improved dramaticay, resuting in faster, smoother workfow, increased cost reductions, and simper processes. With such systems and equipment, one person can function as the conventiona director, switching operator, system engineer, and graphic designer. In the case of OB vehices, additiona requirements are a wider and more comfortabe work space, ightweight equipment and ower power consumption. As the systems, equipment and workfow get better, the quaity of created video content meeting broadcasting needs must aways be supported by accurate checking and evauation of the fina images and signas. The monitor has a critica roe in this process. So has the operator, who needs a good knowedge of the various standards on broadcasting, signas and coors which the monitor shoud satisfy and of how to use these functions correcty. In addition to conventiona CRT TVs, new TVs using new fat dispay devices such as LCD TVs are spreading rapidy into the retai market. Video content creators must be aware that their work wi be dispayed on LCD TVs as we as the CRT TVs. LCD monitors are aso quicky repacing CRT monitors in the the professiona broadcasting industry. However, due to the differences between LCD and CRT technoogies, the best use is not currenty being made of either. This document covers preparations before using the monitor, usefu functions that the monitor must perform, and technica basics on the monitor such as the differences between CRT and LCD devices, broadcasting standards, signa standards and coor reproduction standards. Read the document through and keep it handy for reference when you choose a monitor to match your usage and environments, or conversey, when you change your environments to suit a CRT or LCD monitor, or when you first use a monitor, etc. This wi hep you to use your monitor appropriatey and make the most of your monitor's performance in creating video content. 2 The Basics of Monitor Technoogy

3 Tabe fo Contents Sony Monitor Lineup and Features... 4 BVM Series...4 PVM Series...4 LMD Series...4 Before Using the Monitor... 5 Checking the Environments of the Instaation Location of the Monitor...6 Iumination...6 Viewing Distance...6 Instaation Location...6 Wa Coor...6 Viewing Ange...6 Warming up the Monitor...8 Adjusting the Monitor...8 White Baance Adjustment...8 Decoder Adjustments...9 CRT Monitor Adjustments Tips on Using the Monitor When the Image is Burred When the Image is too Bright or Dark When the Marker Gows When Back is Foating Technica Basics Teevision Systems Coor Reproduction in the Monitor Three Primary Coors Phosphor Coor Temperature Decoder Characteristics Video Signa Standards Anaog RGB Signa Component Signa Y/C Signa Composite Signa SDI/HD-SDI Signa Devices Used in Monitors CRT LCD Evauation Points for CRT Monitors Horizonta Resoution Vertica Resoution Evauation Points for LCD Monitors Horizonta Resoution Resoution Viewing Ange Contrast Ratio and Luminance Coor Gamut Gray Scae and Gamma Curve Response Speed Interace/Progressive (I/P) Conversion Video Frame Deay Sony Monitor Lineup and Features Before Using the Monitor Tips on Using the Monitor Technica Basics Terminoogy Terminoogy Index The Basics of Monitor Technoogy 3

4 1 Sony Monitor Lineup and Features Sony suppies various monitor modes in order to meet the requirements of appications used in broadcasting, video post production, instrumentation, and genera industry. This section gives an outine of each monitor series. For the detais, access BVM Series A BVM-series monitor is a top-quaity CRT monitor used mainy as a master monitor for broadcasters and production houses. Normay, each video editing system has one master monitor for performing technica picture evauation, such as noise eve checks, coor accuracy, and back detai judgments, for evauating created work. The BVM-series monitor is equipped with various functions to fufi the mission of master monitor; consequenty, the operator needs technica knowedge to manage these modes. LMD Series An LMD-series monitor is the newcomer LCD (Liquid Crysta Dispay) technoogy used mainy as picture monitors or foor monitors by broadcasters and production houses. Their ightweight and sim design aso make them suitabe for use in outdoors and in OB vehices. Normay, each video editing system or production system in an OB vehice has severa picture monitors to check video sources. The LMD-series monitors are aso used by companies and schoos for image processing and aboratory work. They are equivaent in functions to the PVM-series monitors. They aso aow connection to a computer or measuring instrument with a computer output in order to meet the demand of new appications such as non-inear video editing. PVM Series A PVM-series monitor is a CRT monitor used mainy as a picture monitor for broadcasters and production houses. Normay, each video editing system woud have severa picture monitors to check input pictures. The PVM-series monitors are aso widey used by companies and schoos for image processing and aboratory work. Athough the functions are imited compared with the BVM-series monitors, the easy-tooperate design is a feature of the PVM-series monitors. 4 The Basics of Monitor Technoogy

5 Before Using the Monitor To get the best performance from the monitor in picture and input-signa evauation, perform the foowing adjustments and checks before using the monitor. Checking the environments of the instaation ocation of the monitor Check the iumination, viewing distance, instaation ocation, wa coor, viewing ange, etc. Warming up the monitor Sony Monitor Lineup and Features Before Using the Monitor Turn on the power and wait unti it is sufficienty warmed up (about 30 minutes). Adjusting the monitor Adjust the white baance, chroma, phase, brightness, contrast, etc. Tips on Using the Monitor Technica Basics Terminoogy The Basics of Monitor Technoogy 5

6 Before Using the Monitor Checking the Environments of the Instaation Location of the Monitor The apparent coor reproduction on the monitor is greaty affected by ambient ight or gare. This section introduces the idea conditions of use for standard-definition (SD) CRT monitors for studio use meeting standards set by SMPTE. Iumination The idea iumination conditions for a monitor are as foows: indirect ighting iumination with a coor temperature near that of the reference white (D65 or D93, depending on the standard in your region/country) Maximum ight around the monitor: 12 cd/m 2 (10% iumination of 120 cd/m 2 white [100 IRE] on a monitor) 30 to 40 ux reaching the operator 20 to 100 ux in cient area or script reading area Wa Coor A neutra tint, especiay neutra gray, is idea for the wa coor of the room where you insta the monitor. The neutra gray area of more than 8 times the monitor screen area is needed. Viewing Ange The idea viewing ange is within 5 degrees from the center of the monitor screen when the operator views the entire monitor screen. Keep the viewing ange within 15 degrees from the center of the monitor screen. Notes on the iumination environments for LCD and CRT monitors The iumination environments greaty infuence the reproduction of back, or the contrast, on LCD and CRT monitors. Under a bright iumination, for exampe, in an office room which has about 500 to 2000 ux, the LCD monitor provides a higher contrast than the CRT monitor. Under a ower iumination, for exampe, in a studio, the CRT monitor has a higher quaity than the LCD monitor. The LCD device contros the brightness by moving LCD moecues with the backight aways it. For this reason, in a dark pace, an LCD monitor screen shows very dim ight eaks from the back image. In a bright pace, however, the LCD monitor is abe to provide a high contrast thanks to its advantage of smaer ight refection. On the other hand, the CRT monitor can cut off the back signa input and reproduce back even in a dark pace. However, its contrast becomes ower in a bright pace, as refected outdoor ight degrades the reproduction of back. Viewing Distance The idea viewing distance is 4 to 6 times the vertica height of the monitor screen area. Note on viewing distance for high-definition (HD) signas When a high-definition (HD) signa is dispayed on the monitor, the idea viewing distance is 3 times the vertica height of the monitor screen area. Instaation Location The idea instaation ocation is 60 to 120 cm (2 to 6 feet) away from the wa at the back of the monitor. 6 The Basics of Monitor Technoogy

7 60 to120 cm 12cd/m 2 or ess Sony Monitor Lineup and Features to 6 times the screen height 30 to 40 ux Before Using the Monitor Tips on Using the Monitor Technica Basics Terminoogy The Basics of Monitor Technoogy 7

8 Before Using the Monitor Warming up the Monitor To perform stabe coor reproduction, the monitor must be warmed up sufficienty. Turn on the power of the monitor, dispay the white signa and eave it in this state for more than 30 minutes. Adjusting the Monitor The monitor is considered a measuring instrument and is required to faithfuy reproduce the input signa. To measure the signa accuratey, the decoder buit into the monitor must be caibrated correcty using a reference signa. Usuay, coor bars such as those specified by SMPTE are used for such caibration. The required adjustment items may differ according to the type of monitor, CRT or LCD, and the functions it provides. LCD monitors White baance adjustment Chroma/phase adjustment Brightness adjustment Contrast adjustment CRT monitors White baance adjustment Chroma/phase adjustment Brightness adjustment Contrast adjustment CRT adjustments (uniformity, convergence, picture distortion, picture position, etc,) White Baance Adjustment On a coor video monitor, white and back in a video image is reproduced by mixing red, green, and bue ight. If the mixture rate is incorrect, for instance, the same white image may be seen reddish or buish. The degree of tint is defined in terms of coor temperature. D65 is normay used as a standard coor temperature for coor video monitors. If a coor video monitor has different coor temperatures at the dark and bright parts of a back-and-white image, coor cannot be reproduced correcty on that monitor. The white baance adjustment sets the coor temperature throughout a back-and-white signa, regardess of its uminance (that is, in the dark and bright parts). Because the white baance has aready been adjusted at the factory, readjustment is not usuay required when you use ony one monitor. However, if you use mutipe monitors side by side, fine adjustment is required to attain identica coor temperature among the monitors. Before adjusting When adjusting singe monitor Prepare caibrated measuring instrument. Input the gray-scae signa from the reference signa source (signa generator) into the monitor to be adjusted. If the monitor is not equipped with automatic white baance adjustment, use a coor anayzer for white baance adjustment. As coor anayzers may not be uniform in quaity depending on the manufacturer or the product, if strict adjustments are required, we recommend that you caibrate the coor anayzer periodicay or before each adjustment or check the adjustment error of the coor anayzer using a precision spectroradiometer, if necessary. When adjusting mutipe monitors Prepare a reference monitor. Input the gray-scae signa from the reference signa source (signa generator) into the reference monitor and the monitors to be adjusted. Measure the reference monitor using a coor anayzer and adjust the other monitors so that the same vaue as that on the reference monitor is obtained, using the foowing adjustment procedures. Adjustment of the dark parts (Bias adjustment) Coor monitors are normay equipped with bias adjustment menus or bias adjustment hoes for the R and B channes. Adjust each channe so that dark area of the gray scae (20% of the video signa input eve) are seen the same as those on the reference monitor. Because the back area is heaviy affected by ambient ight, decrease the ambient iumination when performing the bias adjustment. Bias adjustment R B If these areas are reddish, decrease the red (R) eve. If the areas are weak in bue, increase the bue (B) eve. Sony broadcast/professiona CRT monitors are equipped with the beam current feedback circuit to maintain stabe white baance for a ong time. 8 The Basics of Monitor Technoogy

9 Adjustment of the bright parts (Gain adjustment) Coor monitors are normay equipped with gain adjustment menus or gain adjustment hoes for the R and B channes. Adjust each channe so that the bright area of the gray scae (100% of the video signa input eve) are seen the same as those on the reference monitor. Gain adjustment CHROMA and PHASE adjustments 1 Input the SMPTE coor-bar signa to the monitor. SMPTE coor bar W Y C G M R B B M C W Bue component Sony Monitor Lineup and Features Red component R B Green component W: white Y: yeow C: cyan G: green M: magenta R: red B: bue Before Using the Monitor If these areas are reddish, decrease the red (R) eve. If the areas are weak in bue, increase the bue (B) eve. The bias and gain adjustments affect each other. Repeat the two adjustments unti the darkest to the brightest part of the gray scae are seen the same as those on the reference monitor. Decoder Adjustments To dispay input composite video or Y/C signas on the monitor's screen, the signas are converted into RGB signas through a decoder. Therefore, the quaity of the decoder and its adjustments markedy affect the monitor's quaity of coor reproduction. Before using the monitor, adjust the decoder precisey using the reference signa. There are four decoder adjustments: chroma and phase adjustments, brightness (back eve) setup and contrast (white eve) setup. The auto chroma/phase setup function on the monitor, if equipped, aows easier setup. Refer to the operating instructions of the monitor for use of the function. As the brightness and contrast cannot be adjusted with this function, adjust them manuay. 2 Set the monitor to the Bue Ony mode. The Bue Ony mode dispays the bue signa component ony as a back-and-white signa. In order to make the adjustment of the decoder easier, the bue signa needs to be ampified. Sony monitors use a system of routing the bue signa to a three coor channes. This provides the operator with a back and white dispay that is brighter and easier to see. CHROMA adjustment PHASE adjustment "Bue Ony" dispay Incorrect chroma and phase (1) (4) (2) (3) If your monitor is not equipped with Bue Ony mode, use a bue fiter for the adjustments. Hod the bue fiter in front of your dominant eye and ook at the monitor's screen. Then, ony the bue signa is seen, with red and green signas invisibe. This is the same effect as Bue Ony mode. (3) (2) (4) (1) (1) (2) (3) (4) Bue component Bue component Bue component Tips on Using the Monitor Technica Basics Terminoogy The Basics of Monitor Technoogy 9

10 Before Using the Monitor 3 Adjust the CHROMA contro so that the brightness of bars (1) and (4) are the same. If you increase the eve with the CHROMA contro, the brightness increases in the order of bars (1) to (4). If you decrease the CHROMA eve, the brightness decreases in the order of bars (1) to (4). Adjust the CHROMA contro in practice unti the upper and ower parts of bars (1) and (4) have the same brightness. 5 As the CHROMA and PHASE adjustments affect each other, repeat steps 3 and 4 unti the brightnesses of a (1), (2), (3) and (4) of the coor bar are the same. Correct chroma and phase (1) (2) (3) (4) Incorrect chroma (4) (3) (2) (1) (1) (2) (3) (4) (4) (3) (2) (1) (1) (2) (3) (4) 6 Reease the Bue Ony mode. (1) (2) (3) (4) 4 Adjust the PHASE contro so that the brightnesses of bars (2) and (3) are the same. (This adjustment cannot be performed for PAL signas and component signas.) Phase determines hue. If phase is incorrecty adjusted, the correct hue is not reproduced, because the ratio of coor components incuded in each of the coor bars is wrong. If it is correcty adjusted, cyan in bar (2), which is a mixture of green and bue, and magenta in bar (3), which is a mixture of red and bue, have the same amount of bue component. As you adjust the PHASE contro, the bue component eve changes symmetricay in bars (2) and (3). Adjust the PHASE contro in practice unti the upper and ower parts of bars (2) and (3) have the same brightness. Incorrect phase (1) (2) (3) (4) (4) (3) (2) (1) Brightness setup It is common that a dark image, which cannot be seen in a bright room during the day, is ceary visibe in a darker room or at night. This is because a dark image on a coor video monitor is seen differenty according to the ambient ight (environmenta brightness). To dea with this phenomenon, adjust the back eve of the video signa (brightness) on the monitor according to the ambient ight and the back eve of the image to be reproduced. 1 Input the SMPTE coor-bar signa to the monitor. 2 Adjust the BRIGHTNESS contro, observing the three back bars in the PLUGE signa section of the coor bar. The three bars show 0 IRE-back (uminance 0), a brighter back 4 IRE, and a darker back -4 IRE. As you increase the eve with the BRIGHTNESS contro, the three bars are seen more distinctivey. As you decrease the BRIGHTNESS eve, -4 IRE bar is seen equa to the 0 IRE bar; thus ony the 4 IRE bar ights very dimy. The monitor is now set up to dispay a 0-IRE signa as the darkest back. (1) (2) (3) (4) 10 The Basics of Monitor Technoogy

11 + Setup eve _ PLUGE signa Setup eve (0 IRE) W Y C G M R B B M C W I W Q 0 IRE 0 IRE 100 % white (brightest white) Readjust the contrast each time ight conditions are changed. Sony Monitor Lineup and Features W B I Y C G M R B M C W W Q 0 IRE IRE CRT Monitor Adjustments Master CRT monitors such as BVM-series monitors are equipped with fine-adjustment functions to improve coor reproduction. This section outines of various adjustments. For detais, refer to the operation manua suppied with the monitor. Before Using the Monitor -4 IRE +4 IRE PLUGE signa Readjust the brightness each time ight conditions are changed. Contrast setup Contrast (white eve) must be adjusted depending on the ambient ight in the same way as brightness is set up. For optimum viewing, higher contrast setup is recommended in a bright room, whie ower contrast setup is more appropriate in a dark room. Set the maximum contrast as high as possibe so that washed-out pictures are not seen. Washedout pictures occur due to white compression, that is, the phenomenon of scan ines overapping on a CRT monitor, and gray scae in the white portion is ost on an LCD monitor. 1 Input the SMPTE coor-bar signa to the monitor. 2 Increase the contrast eve with the CONTRAST contro to the extent that the 100-IRE white (the brightest white) in the coor bar is not a washed-out or booming picture. If the contrast is too high, washed-out pictures occur and degrade the resoution. Uniformity adjustment The uniformity adjustment corrects to attain even coor reproduction on every portion of the screen. Dispay an a-white signa on the monitor and adjust the uniformity to reproduce a fat and uniform white on every portion of the screen. good bad Convergence adjustment The convergence adjustment exacty registers red, green, and bue ines to make a white ine. If the three ines are shifted, coor fringing may occur. To adjust the convergence, dispay a cross-hatched pattern on the monitor; then, if the red, green and bue ines are not converged, move the shifted ine up, down, eft, or right so that they are competey white or correcty converged. Tips on Using the Monitor Technica Basics Terminoogy The Basics of Monitor Technoogy 11

12 Before Using the Monitor Image distortion correction Dispay a cross-hatched pattern on the monitor and correct image distortion on the entire screen, such as inearity and pincushion distortion. Linearity Correct uneven spaces between ines so that the ines are aigned with the same interva (or distance) and the same squares are equa in the center and periphera areas of the screen. Pincushion Correct curved ines to make straight, vertica, and horizonta ines. good bad Picture position adjustment Dispay a monoscope pattern on the monitor and adjust the position of the pattern. Foucus adjustment Adjust the focus so that the ion s face on the upper part of the monoscope pattern is ceary visibe. 12 The Basics of Monitor Technoogy

13 Tips on Using the Monitor This section introduces usefu operations of the monitor whie you are editing videos. After performing the adjustments and checks foowing Before Using the Monitor, read this section and operate the monitor as required. When the Image is Burred Adjust the sharpness, using the aperture contro. Increase the sharpness and view the monitor image from a distance of 2 to 3 meters (7 to 19 feet). The image becomes cear. This function is usefu when you evauate the monitor. Adjust the aperture contro to decrease the sharpness if the edges of the image are too enhanced. When the Image is too Bright or Dark If 75-ohm termination is disabed, the image on the monitor is too bright and oses detai. Make sure that the termination is abed. VIDEO OUT VIDEO 75Ω ON There are three termination methods depending on the unit ohm termination connector: BVM-series monitors, measuring instruments 2. Termination switch equipped on the unit: VTR, etc. 3. Automatic termination: PVM-series monitors, LMD-series monitors For method 1, connect the termination connector to the video output connector on the unit. For method 2, set the termination switch to ON. For method 3, check that a BNC connector is connected to the video output connector and the other end of the cabe is free (case A), or a BNC-RCA pug adaptor is connected to the video output connector and no cabe is connected to the adaptor (case B). In case A, disconnect the cabe from the video output connector or connect the cabe to other equipment. In case B, disconnect the pug adaptor or connect a cabe to the pug adaptor and other equipment. If there is no case A or B, and nothing is connected to the video output IN connector, the termination section may be damaged. Ask for repair of the monitor, or connect a termination connector. If the image is extremey dark, the automatic termination may not be deactivated even when a cabe is pugged into the video output connector. This phenomenon tends to occur when the pins of the cabe are damaged. Try to use a new cabe for the connection. When the Marker Gows If a high marker eve is set, and the uminance of the marker is too high, the marker gows. Lower the uminance of the marker using an adjustment menu, such as Marker Leve of the User configuration menu, etc. (The marker-eve menu is not provided with some monitor modes.) When Back is Foating The back setup eve may be incorrect when an NTSC or 480/60I component signa is dispayed. Adjust the setup eve as in the foowing tabe. Area North America South America Argentina, Paraguay, Uruguay Other areas Setup eve 7.5 IRE 0 IRE 7.5 IRE Africa, Austraia, Europe, the Midde East 0 IRE Asia except Japan NTSC area 7.5 IRE PAL area 0 IRE Japan 0 IRE Sony Monitor Lineup and Features Before Using the Monitor Tips on Using the Monitor Technica Basics Terminoogy The Basics of Monitor Technoogy 13

14 Technica Basics Technica Basics When someone ooks at an object, he/she recognizes its coor when the ight refected by the object passes through the retina and the stimuus reaches the brain. With this mechanism, we can recognize a wide range of coors. On a camera or monitor, the input information of the ight refected by the object is separated into three primary coors (R, G, and B), which pass through mechanisms in the monitor to integrate, and finay are dispayed as the object with its coor and shape on the screen. The range of coors that the monitor expresses and communicates is imited compared with human coor perception. The different mechanisms may make differences in coors among the coors the human brain can recognize, the coors deveoped within the system and the coors reproduced by a monitor. This is the reason why many standards and reguations are defined regarding the teevision system and coor reproduction on the monitor. Today, video content is created and edited by broadcasters and production houses a over the word, but they are checked and evauated in accordance with the same standards. This section introduces basic information on the standards and reguations, to hep you make best use of the monitor. Teevision Systems To make compatibe communication possibe, there are two main teevision system groups reguating video information (three primary coors) in the word. Broadcasters a over the word deiver video content according to the foowing two teevision systems: Coor Reproduction in the Monitor Three Primary Coors If you enarge a monitor screen, you can see red, green, and bue ight emission. The monitor reproduces coors in combination of three coor ights, the so-caed three primary coors. NTSC system Empoyed in North America, Centra and South America, Japan, etc. Red Back PAL/SECAM system Empoyed in Europe, Singapore, Hong Kong, Brazi (PAL-M), etc. Yeow White Magenta Green Cyan Bue Each group defines the chromaticity of the three primary coors and the reference white as foows: Additive mixture of coors NTSC PAL/SECAM x y x y Three primary Red co- ors Green Bue Reference white Standard source C Standard source D65 Phosphor The CRT (Cathode Ray Tube) is a device to express video information transmitted from areas in the word according to the teevision systems (NTSC, PAL) of the word. The surface of the CRT is coated with red, green and bue phosphors. When the eectron beam emitted from the CRT hits a phosphor, ight is emitted, and that coor is produced on the monitor screen. The chromaticity of these phosphors for each primary coor must stricty conform to the teevision system's standards (NTSC, PAL) and be compatibe with the input video signa. The foowing two standards are appied to the phosphors, based on the chromaticity points defined by CIE (Commission Internationae de Ecairage). 14 The Basics of Monitor Technoogy

15 EBU: Standard for phosphors determined by EBU (European Broadcasting Union), based on the CIE chromaticity points The EBU standard is integrated with the three primary coors of the PAL system. The EBU standard is aso empoyed as the standard for studio video monitors in Japan. SMPTE-C: Standard for phosphors determined by SMPTE (Society of Motion Picture and Teevision Engineers), based on the CIE chromaticity points The SMPTE-C standard is determined as the officia standard for studio video monitors by SMPTE. The chromaticity points of phosphors are based on those empoyed by Conrack Co. in North America, because the theoretica three primary coors of the NTSC teevision system empoyed in North America and Japan cannot be reproduced on CRTs. Every Sony professiona/business-use monitor uses a CRT that satisfies the EBU or SMPTE-C standard. (As an exception, there are some ow-price modes whose CRTs are corresponding to these standards [with a wider toerance range] or empoy unique phosphors). y EBU GREEN SMPTE GREEN SMPTE RED EBU RED LCD (Liquid Crysta Dispay) The Sony LMD-series monitors use LCD instead of CRT dispay. Previousy, LCD monitors were considered unsuitabe as professiona monitors, since strict accurate coor reproduction is required for professiona appications. The use of high-uminance and high-contrast LCD panes with newy deveoped coor fiters offering exceent coor reproduction affords the LMD-series monitors quaity and accuracy cose to CRT monitors, athough the toerance range is wider than the CRT monitors. (Some ower-price modes empoy LCD panes with a imited coor gamut and a narrower viewing ange to meet their appications.) Coor Temperature The coor of an object we usuay see is caed object coor. It is the coor of the ight refected from the object iuminated by a ight source. In contrast, the coor of ight that a ight source emits itsef is caed ight coor. A coor of the image on a monitor is ight coor. The chromaticity of a ight source is represented in units of kevins for the physica quaity coor temperature. The coor temperature is defined by heating a back body eement such as carbon or tungsten (back body absorbing a radiation without transmission or refection). When a back body is heated, it wi start emitting ight when it reaches a certain absoute temperature (expressed in K [kevins]). This is caed coor temperature. The higher the coor temperature, the more buish the object ight; the ower the coor temperature, the more reddish the object ight. The chart beow shows the chromaticity of a back-body radiant curve. Sony Monitor Lineup and Features Before Using the Monitor Tips on Using the Monitor EBU BLUE SMPTE BLUE X CIE chromaticity diagram y G Back-body radiant curve (Unit: K) Technica Basics Chromaticity for high-definition system The chromaticity of the three primary coors and the reference white for the high-definition system are defined by ITU- R BT. 709 as foows: ITU-R BT.709 X Y Three primary coors Red Green Bue Reference white Standard source D W R B X Back-body radiant curve on the CIE chart 0.8 Terminoogy The Basics of Monitor Technoogy 15

16 Technica Basics In reaity, we ive in environments under sunight. The coor temperature under sunight is sighty different from the back body radiation. For this reason, the dayight curve is made by tracing coor temperatures of a standard ight source artificiay imitating sunight. D in standard source D65, for exampe, means dayight. y D Dayight D curve D K 5500 D K Same coor temperature ine Back-body radiant curve 0.40 X Dayight curve and back-body radiant curve Standard source D75 This is coor temperature of 7504 K (not present in a backbody radiant curve). The coor is defined as sky-tones in northern countries. Standard source D93 This is coor temperature of 9305 K (not present in a backbody radiant curve). The standard reference white for studio monitors in Japan. Decoder Characteristics To reproduce the input RGB signas accuratey in the NTSC system, B-Y and R-Y signas must be decoded with a phase of 90 degrees. Whie the decoding axis of professiona monitors is set exacty to 90 degrees, that of consumer TVs is set to 110 degrees in order to reproduce bright skin tones. Further, the decoding axis setting of consumer TVs differs depending on the manufacturer. Consequenty, accurate coor reproduction cannot be obtained with consumer TVs even if you perform the chroma and phase adjustments. Corrected decoding axis and ampitude correction ratio (B-Y axis as reference) Corrected R-Y axis (95 ) Origina R-Y axis (90 ) Standard ight sources defined by CIE Standard source A This is coor temperature of ight emitted from a tungsten amp of 2856K. The coor is equa to the ight emitted from a back body of the same temperature. Standard source B Back-body radiant 4874 K, or ight cose to average sunight at noon. Standard source C Back-body radiant 6774 K, or ight cose to average dayight. Origina G-Y axis (237 ) 1.0 (0.34) (0.31) (0.56) Corrected G-Y axis (239 ) Phase adjustment Chroma adjustment (1.0) Corrected/origina B-Y axis (0 ) (reference) Standard source D65 This is coor temperature of 6504 K (not present in a backbody radiant curve). This ight is considered cosest to actua ambient ight, incuding dayight and utravioet rays. PAL/SECAM reference white. Reference white in the standard for studio monitors in both the NTSC and PAL/SECAM areas. The white baance of a video monitor must be adjusted to this coor. Popuar coor temperature used a over the word. Standard source D55 This is coor temperature of 5503 K (not present in a backbody radiant curve). The coor of sunight with sky-tones added. 16 The Basics of Monitor Technoogy

17 Video Signa Standards This section introduces the features of various video signas that can be input to monitors. Anaog RGB Signa The RGB signa is a source signa. It provides the highestquaity video signa, but has too great a voume of information to be recorded or transmitted. Component Signa The video quaity is cose that with an RGB signa. It is separated into a uminance (Y) signa and coor-difference signas (R-Y and B-Y), and is capabe of high recording quaity whie maintaining exceent coor reproduction and coor resoution. Y/C Signa It is separated into a uminance (Y) signa and chrominance signa (C), and it eiminates subcarrier eakage and cross coor artifacts caused by the interference between the two signas. The disadvantages are shorter transmission distance and the need for a pubic-use 4-pin mini DIN connector whose pins tend to break. Composite Signa The composite signa incudes the uminance signa (Y) and chrominance signa (C) to form one signa. This is most popuar video signa. It can be transmitted over a ong distance using ony one cabe and aows ong recording time. SDI/HD-SDI Signa The SDI signa is a component digita signa conforming to the SMPTE259M/ITU-R BT.656 (CCIR656-III) Seria Digita Interface (SDI) standards, and the HD-SDI signa is that conforming to the SMPTE292M High Definition Seria Digita Interface (HD-SDI) standards. It is the digita form of the component signa. The SDI signa enabes transmission of high-quaity video and audio via a singe coaxia cabe. It is popuar with broadcasters and production houses, because it is not affected by noise interference as compared with anaog signas. Sony Monitor Lineup and Features Before Using the Monitor Tips on Using the Monitor Technica Basics Terminoogy The Basics of Monitor Technoogy 17

18 Technica Basics Composite Y/C Y/R-Y/B-Y RGB Y signa Moduation of coor difference signa Y signa R signa (In case of NTSC) C signa 2 4 R-Y signa G signa B-Y signa B signa Photoeectric conversion V + Y C Moduation circuit Y R-Y B-Y Matrix circuit Digita processing circuit B G R A/D A/D or D composite Y/C component composite Digita component Digita composite Y/C component Digita component Anaog RGB V Composite signa Y/C separation circuit Y Y R C Y/C signa D/A Demoduation circuit R-Y B-Y Matrix circuit G B CRT 18 The Basics of Monitor Technoogy

19 Devices Used in Monitors CRT A CRT (Cathode Ray Tube) is a device used in the BVM and PVM series monitors. When the cathode is heated, eectrons are emitted and attracted to the anode by high votage suppied to the ast grid. Coors are produced when the acceerated eectrons hit the RGB phosphors. To reproduce an image accuratey on the surface with the RGB phosphors, an eectronic ens and coor-separating mechanism are present in the CRT gun. A defection yoke is used to scan the eectron beams across the CRT picture area. Anode Eectron gun (Cathode) Aperture Grie (AG) In recent years, thanks to the progress in gass design and eectron-gun technoogy, both types have achieved a fat screen for TV and computer dispay. From a standpoint of doming, however, Trinitron sti has an advantage. About the AG pitch In the Trinitron CRT, eectron beams pass through sots of the Aperture Grie and hit phosphor stripes organized as red, green, and bue. The distance between sots of the Aperture Grie is caed AG pitch, expressed in units of miimeters, The finer the AG pitch, the more detaied the image and the higher the resoution. The advantage is that due to its structure, it can easiy expand with heat, eiminating purity probems. Aperture Grie (AG) Phosphor surface R G B Sony Monitor Lineup and Features Before Using the Monitor Vertica inear face There are two types of coor-separating mechanisms: Trinitron and Shadow Mask. Trinitron empoys a bind-type Aperture Grie (AG), and Shadow Mask empoys a attice-type mechanism which ooks ike sma hoes. The Aperture Grie has a very fine damper wire to absorb any horizonta vibration due to its very fine diameter. Eectron beams AG pitch Tips on Using the Monitor Aperture Grie (AG) Damper wire Trinitron Phosphor Technica Basics Advantages of Trinitron compared with Shadow Mask Low ambient ight refection in the vertica directions Good inearity in the vertica directions High brightness and contrast Less doming caused by the expansion of the coor-separating mechanism under increased heat Terminoogy The Basics of Monitor Technoogy 19

20 Technica Basics LCD LCD (Liquid Crysta Dispay) is a device used in our LMD series monitors. In order to expain the basic structure and theory of the LCD, the foowing introduces the technoogies of a TN (Twisted Nematic) LCD device which is empoyed in ow-priced LMDseries monitors. On a TN LCD, two poarizing fiters positioned adjacent to each other at an ange of 90 degrees sandwich the iquid crysta materia. When iquid crysta is rotated perpendicuar to the poarizing fiters, the ight passes through the first poarizing fiter and is interrupted by the second poarizing fiter. By appying a votage potentia across the iquid crysta, the crysta s moecues orient perpendicuar to the eectric fied, that is, in ine with the poarizing fiters. This aows the ight to pass through both fiters. The ight-transmission rate is controed by changing the votage potentia and thus the orientation ange of the iquid crysta s moecues. Unike a CRT, LCD is a dispay with fixed picture eements, and high-speed contro of the picture eements is needed. For this purpose, TFT (Thin Fim Transistor) is mounted to each pixe. Because the mounting of TFT requires high-precision processing technoogy, its productivity was ow and arge-sizing of screens was neary impossibe. In recent years, however, the LCD industry has become prosperous and technoogica innovation has remarkaby progressed, promoting rapid arge-sizing of screen. The newy-deveoped technoogy aso improves the viewing ange, previousy an inherent disadvantage of the LCD monitor caused by the change in screen brightness or coor reversing because of the LCD materia structure. The LMD-series monitors use appropriate technoogies according to usage, required specifications, price, etc. Eectrode (scan ines) Back ight Poarizing fiter Gass Opposit Eectrode Eectrode Gass Poarizing fiter TFT (Thin Fim Transistor) R G Liquid crysta B Coor fiters R G B OFF OFF ON Back ight Transparent Eectrode (data ine) Coor fiters Poarization direction Liquid crysta Signa X Eectrode Y Eectrode Poarization direction 20 The Basics of Monitor Technoogy

21 Evauation Points for CRT Monitors The evauation points of the image quaity of broadcast/professiona CRT monitors are the foowing: Coor gamut and accuracy Uniformity Purity Convergence Linearity Stabiity of high votage circuit Horizonta resoution Horizonta Resoution Horizonta resoution is defined by the number of TV ines that exist within an area where the screen width is the same as screen height. A theoretica vaue of the horizonta resoution for the Trinitron monitor is the number of sots of the aperture grie (75% the width of the monitor screen). However, the actua horizonta resoution vaue is not uniform, because of the frequency-response characteristics of circuits, beam-spot size, and other factors. 4 Sony Monitor Lineup and Features Conventionay, horizonta resoution has been an important point for evauating the genera picture quaity of broadcast/ professiona CRT monitors. This is because horizonta resoution can simpy represent the picture reproduction quaity of a CRT by a numerica vaue, athough the quaity depends on mutipe factors in product design and manufacturing, such as the pitch difference of the coor-separating mechanism, focus characteristic, interaced scanning accuracy and circuit characteristics. 3 3 Before Using the Monitor Horizonta resoution is measured by eye, by inputting the resoution chart in the sti-picture mode into a monitor. As the CRT monitor has a superior response speed, it is known by experience that the horizonta resoution for a sti picture can aso be used as an index for evauating the quaity of motion pictures. Here we introduce horizonta resoution and vertica resoution as evauation points for broadcast/professiona CRT monitors. Aperture Grie White 1 ine Back 1 ine Enarged view... White 1 ine Back 1 ine R G B R G B R G B R G B Tips on Using the Monitor Technica Basics Terminoogy The Basics of Monitor Technoogy 21

22 Technica Basics Vertica Resoution Vertica resoution is the capabiity of a monitor to accuratey reproduce horizonta stripes in the video signa. Vertica resoution is determined soey by the scanning system. Vertica resoution is cacuated as foows: If the number of scan ines is 525 in the NTSC system, then the number of scan ines within the effective area is 483. Cacuating the reationship between the scan ines and horizonta stripes according to statistics, 483 approximatey 0.7 = approximatey 340 (ines) yieds the vertica resoution. Vertica resoution does not differ greaty depending on the performance of the monitor, but its vaue may decrease owing to interace ratio and focus characteristics. To maintain high vertica resoution, Sony monitors empoy efficient circuits and CRTs. Vertica resoution is 10 ines Scan ine Evauation Points for LCD Monitors The evauation points of the image quaity of broadcast/professiona LCD monitors are the foowing: Horizonta resoution Resoution Viewing ange Contrast ratio and uminance Coor gamut Gray scae and gamma curve Response speed Interace/Progressive (I/P) conversion Video frame deay Horizonta Resoution Unike a CRT, an LCD has fixed picture eements and the maximum resoution is determined by the number of picture eements. In addition, the changing speed of crysta moecues may differ greaty or the interace/progressive conversion method may differ between the sti image and the motion picture depending on the LCD product. For these reasons, horizonta resoution measured by the sti image chart is not aways reiabe for motion picture quaity, even if the LCD has the same number of picture eements. Athough, for a CRT monitor, horizonta resoution for the sti image can be used as the index for the motion picture quaity, the quaity of an LCD monitor must be judged accuratey and generay, not ony with the horizonta resoution vaue (TV ines) described in the specifications in the cataog and the evauation for the sti image, but aso with the evauation of actua motion picture dispay. When you compare an LCD monitor with another LCD monitor or with a CRT monitor, it is advisabe to consider your instaation environments and other factors as we as the horizonta resoution. Resoution Resoution is defined by the horizonta and vertica numbers of picture eements. In case of a computer signa, the maximum image quaity is usuay obtained when the number of picture eements of an image is the same as those of the LCD. In case of a video signa, however, the resoution sensed by eye may not accord with the actua number of picture eements. This is because the resoution is greaty infuenced by the characteristics of the signa processing circuit, such as the reation between the resoution of the input signa and that of the LCD, the input signa quaity, the interace/progressive conversion, the scaing, etc. The resoution sensed by eye is aso infuenced by the instaation environments of the LCD monitor, uminance of the LCD pane, contrast, response speed, etc. 22 The Basics of Monitor Technoogy

23 Viewing Ange For monitor specifications, viewing ange is defined as the ange within which the contrast ratio is higher than 10:1, both horizontay and verticay. When you can see the monitor to evauate, it is advisabe to observe the change in contrast not ony from the front but aso from the sides and various anges. Even if the contrast is good when you see the image from the front, it may decrease greaty if you move away from the front. The viewing ange evauation by eye is aso infuenced by ambient ight conditions. It is advisabe to evauate the contrast under both a bright ight and a dark ight. Contrast Ratio and Luminance For monitor specifications, contrast ratio is defined as the vaue obtained when the uminance of back is divided by the uminance of white. The LCD has a high contrast in bright environments because the back ight is aways it and the refection of outer ight is reduced. If the coor fiters are thin and coated with reduced coors, the coor gamut becomes narrower but a higher uminance is obtained. If the monitor is opticay designed so that the diagona contrast is reduced and the back ight focuses on the front of the monitor, the uminance seen from the front is high but the contrast in actua use decreases greaty if you move from the front of the monitor, resuting in an impression of a narrower viewing ange. Luminance aso greaty infuences the duration of the back ight. In a dark room, you may fee that the contrast on the monitor with a ower contrast vaue in its specifications is higher than that on the monitor with a higher contrast and uminance vaues. This is because the former monitor has a ower back uminance vaue than the atter. Maximum uminance Contrast ratio Back uminance Monitor A 330 cd/m : cd/m 2 Monitor B 200 cd/m : cd/m 2 Coor Gamut As the coor gamut is usuay not announced officiay, it must be checked by eye or using a coor anayzer. The coor gamut is determined mainy by the optica design of coor fiters and back ight, but it is said that the manufacturing quaity of LCD monitors is not uniform compared with that of CRT monitors. As mentioned before, coor gamut has a cose reationship with uminance. Gray Scae and Gamma Curve The specifications of gray scae and gamma curve are rarey announced officiay. Mainy a 6-bit or 8-bit driver is used for the LCD. The gamma curve of some LCD devices has S- type characteristics. To evauate the gamma curve and the gray scae, output the gray scae chart. Response Speed For monitor specifications, the response ratio is normay defined by adding the time eapsed when the coor on the monitor screen changes from back to white at room temperature and the time eapsed when it changes from white to back. It is advisabe that you confirm the definition of the specification because some monitors show their response speed as either the time eapsed when the coor on the monitor screen changes from back to white or the time eapsed when it changes from white to back. Further, some LCD devices have characteristics of a sower response ratio in the midde stage of gray scae, that is, between back and dark gray, or between white and ight gray. In concusion, it is advisabe to check the response speed of motion pictures by eye. The response speed decreases as the temperature owers. The response speed may affect the actua video production and editing, for exampe, deay of video frames. Interace/Progressive (I/P) Conversion Check the interace/progressive conversion carefuy, as there are different methods. Jaggy noises and diagona ine ficker noises may occur depending on the method of interace/progressive conversion. Some methods have different systems for processing of sti images and for motion pictures, in order to achieve the appropriate processing independenty. Some methods may cause a deay in image dispay to the input signa. Video Frame Deay Video frame deay is affected by the response speed of the LCD and signa processing by I/P conversion. As the monitor specifications sometimes indicate deay by signa processing ony, you aso need to consider the deay by the response speed of the LCD. Sony Monitor Lineup and Features Before Using the Monitor Tips on Using the Monitor Technica Basics Terminoogy The Basics of Monitor Technoogy 23

24 Terminoogy A Terminoogy aperture contro A circuit that appies edge enhancement or edge correction to a video signa. Eectricay generated edge-enhancement signas ( preshoot at the eading edge and overshoot at the traiing edge) are added to the origina video signa for edge enhancement. Too much enhancement may resut in a booming picture. Enhancement aso reduces picture resoution. B beam current feedback circuit A circuit that stabiizes the coor baance of a CRT monitor. Long-term charges in the eectron gun of the CRTs used in coor video monitors can resut in an imbaance among R, G, and B, which causes a shift in the coor baance of the dispay. This phenomenon is corrected by the beam-current feedback circuit, which detects the cathode current of the gun and maintains a tabe of baance data for a ong time to be referenced for automaticay adjusting the CRT drive circuits. This technoogy was first deveoped for the Sony BVM series broadcast monitors. It can be seen at the top of the raster just above the picture as Red, Green and Bue horizonta ines. back-and-white TV standards There are two standards for back-and-white video signas: CCIR and EIA. The CCIR system is the European standard, having 625 horizonta scan ines. The EIA system is the American standard, having 525 horizonta scan ines. The differences in specifications are shown in the tabe beow. System CCIR EIA Scan ines Horizonta scanning frequency khz khz Vertica scanning frequency 50 Hz 60 Hz Interace 2:1 2:1 Compatibe coor system PAL, SECAM NTSC Deveoping country France U.S.A. bue ony A function to show ony the bue coor component of a dispayed signa. This function is used to adjust the decoder of a coor video monitor (CHROMA and PHASE) and to check for noise on signas using a coor-bar signa. Some monitors show ony the bue signa component on dispay. However, most Sony coor video monitors show the bue signa as a back-and-white dispay providing a bright screen to faciitate adjustment. Both types have the same function. brightness (back-eve) setup The eve of the back signa that functions as the reference eve for video signas. In North America, 7.5 IRE is specified as the setup eve and 0 IRE in other areas. If a monitor is not adjusted to match the setup eve of the input video signa, the dispayed image becomes to dark or too ight. C CCIR Abbreviation for Comite Consutatif Internationa des Radio- Communications. CCIR has been merged with ITU and is currenty caed ITU-R. CIE Abbreviation for Commission Internationae de Ecairage coor bars A reference signa to be used for checking the coor reproduction of coor video monitors and VTRs. There are seven vertica coor bars: a white bar on the very eft foowed by six coored bars to the right. These coor bars are in descending order of each coor s uminance vaue. A fu-fied coor-bar signa, spit coor-bar signa, SMPTE coor-bar signa are used. comb fiter A fiter which can separate the uminance (Y) and chrominance (C) components of video signas with high accuracy using the correation characteristics among other scan ines. It does not aow deterioration of horizonta resoution, unike trap fiters. A two-ine comb fiter uses the correation of the scan ines; thus, vertica resoution decreases, and dot noise aong the horizonta ines appears when reproducing horizonta stripes. This shortcoming is improved by a three-ine comb fiter, which uses an image of two horizonta scan ines (those before and after the present scan ine). A more sophisticated three-dimensiona comb fiter, which not ony utiizes the correation among scan ines but aso fieds, is aso avaiabe. cross coor A phenomenon that causes a rainbow effect to appear on a specific image, such as a shirt with a striped pattern. This is caused by crosstak when the Y- signa component is present in the C signa because of incompete Y/C separation. CRT (Cathode Ray Tube) A device to reproduce images by emitting eectron beams generated by a high votage circuit though a vacuum gass tube and hitting coor phosphors. 24 The Basics of Monitor Technoogy