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For CAD and desktop publishing Philips Brilliance 21A autoscan monitor Announced by Philips in late 1994, the Brilliance 21A is a radical new development in computer monitors. Not only are all its specifications such as convergence under digital control but it even compensates for variations in the Earth’s magnetic field. By BOB FLYNN Ever since this new range of monitors was released, they have been in short supply but after a very long wait, we finally received a sample unit to review. It was quite an experience. We have a number of large screen monitors in the SILICON CHIP offices but for sheer size, the Brilliance 21A monitor puts them in the shade. It’s not so much that it has a large screen but its cabinet is quite bulky and heavy. Its overall dimensions are 528 x 540 x 501mm (W x H x D). So you need a large desk for one of these monitors and you need two men to lift it safely since it weighs 37 kilograms. The Brilliance 21A has a 54cm, flat, black matrix, square CRT with a dot pitch of 0.28mm, currently the best that can be made. The screen is anti-reflection and antistatic treated. Maximum resolution is 1600 x 1280 pixels although that does not tell the whole story. While many monitors can be switched to 1600 x 1280, their resulting picture may not be useable. The Bril­liance 21A, on the other hand, has been electronically tweaked to obtain the very best picture that can be obtained from existing 0.28mm dot CRT technology. In fact, it could be said the picture quality is theoretically better than is possible. We’ll see why, later. As with all large screen monitors, 8  Silicon Chip the Brilliance is an autoscan model and will automatically cope with horizontal scan rates from 30-82kHz and vertical scan rates from 50-160Hz. Video input is RGB analog and typical sensitivity is 0.7V. Video band­width is 150MHz and input impedance 75 ohms. Three modes of sync are accepted: composite sync on the green line, separate com­ posite TTL sync (positive or negative) and separate TTL Horizon­tal and Vertical sync (positive or negative). The monitor also has the following features: (1) digital control of contrast and brightness over the full screen, the brightness uniformity being better than 90%; (2) digital control of convergence so that it is better than 0.2mm (typically 0.15mm) over the full screen; and (3) automatic cancelling of the earth’s magnetic field through a magnetic sensor and a proprietary cir­cuit that maintains a constant magnetic field inside the monitor. This ensures that distortions of the display caused by changes of the position of the monitor do not occur. Power management Naturally, this monitor has energy saving features and they are quite comprehensive. It is TCO 1992 Power Management/Energy Star Power Management compatible. This requires a VESA-DPMS compliant signal. With screen saver programs, the power consump­tion drops 10%. With computers with VESA Display Power Manage­ment, the power consumption drops from a maximum of 180W to 15W, after one hour without vertical and horizontal sync signals. When sync signals are restored, recovery to normal operation takes less than 3 seconds. After a further one hour without sync signals, the monitor switches to its lowest power state, consum­ing a maximum of 8W. Recovery time from this state is the same as the normal switch-on period. The power state in these reduced modes is shown on the LCD panel. Storage in the monitor’s memory of 21 different graphic resolution files, 12 factory preset and nine user generated, is possible. Software is supplied with the monitor that allows the user to adjust the image for the correct size and centring and generate a correction table for the control of convergence, brightness and colour uniformity, if the application is not covered by the default files. Black screen Apart from the size, the first thing that most people notice about this monitor is the “blackness” of the screen. It certainly has the blackest screen we have seen. Apart from this the 21A looks very much like any other digital monitor. At the bottom centre of the front is a yellow backlit liquid crystal display, flanked on either side by a group of four push­buttons. Further to the right of these are controls for brightness and contrast and the power switch. The buttons to the left of the display are Function, Adjust (+), Degauss and Adjust (-). The + and - buttons each you need to store your mode by pushing the channel select button to select one of the user file memories (13-21). Error messages If no connection can be made between the monitor and your computer, the LCD will display an error message such as “Missing H sync”, “Missing V sync” or “Missing H & V sync”, meaning that cables are improperly connected or the computer is not switched on. The messages “V out of range” or “H out of range” mean that the vertical or horizontal scan frequencies of your computer are outside the monitor’s 50-160Hz vertical or 30-82kHz horizontal scan rates. Five additional error messages may be displayed to indicate monitor faults. Geometry & convergence For our tests, the Brilliance 21A was connected to a 486DX and used with programs operatThe model 21A is the top model in the Philips Brilliance range of monitors. It has ing at various resolutions from digital control of all picture parameters and automatic compensation for variations 800 x 600 to 1280 x 1024 pixels. in external magnetic fields. For the two highest resolutions, the message “Mode not found” allow adjustment of the geometry and internal microprocessor. A two-posi- was displayed and so we went through colour temperature through a scale of tion slide switch selects either 75-ohm the procedure for creating user gener0-9, indicated on the LCD. The buttons input impedance or high impedance. ated files. The supplied soft­ware runs to the right of the display are Memory With only one monitor connected to from Windows and involves linking Select, Memory Store, Memory Recall your computer this switch should be selected channels to user tables. This and Input select. in the 75-ohm position. The high im- done, Geometry Adjust was carried Pressing the Function button ac- pedance position should only be used out. This entails adjusting the raster cesses the following 10 functions if two monitors are connected to your to screen centre and setting the vertise­q­u en­t ial­l y: Horizontal position, graphics card. cal and horizontal borders to a width Width, Vertical position, Height, ColAt switch-on the LCD panel displays depending on the resolution for which our temperature, Pincushion, Pincush- the message “Wait...start up”, followed the table was being made. ion balance, Trapezoidal, Trapez­oidal by “F/W Release..(No.)”. Each of these The next step is to Select Reference balance and Language. messages display for 1-2 seconds and Points. A green mark has to be moved The colour temperature function are then followed by the message to the top left of the screen and a secallows the choice of either a 9300° or “Test in progress”. This message is ond green mark moved to the bottom 6500° white. A third choice allows displayed for 2-3 seconds while the right of the screen. The program then the operator to set his own colour monitor does its self checks. If the creates the correction table for brighttemperature by the adjustment of the moni­ tor recognises the timing sup- ness and convergence of the operating red, green and blue mixture using the plied by your video card as one of its mode. The files so created should be + and - pushbuttons. default modes the LCD will show the saved to the hard disc so that the chanOn the rear of the monitor is a power resolution being used. If it does not, nel settings can be restored if re­quired input socket (the monitor can operate then the message “Mode not found” at a later date. from 90-132VAC and 180-264VAC, 47- will be displayed. Why do all this? Because the Philips 76Hz auto selected) and five BNC sockThis means that the current timing Brilliance 21A is capable of much ets for the signal connections. A 15-pin is not stored though the monitor is better convergence than typical comMini D-Sub socket for video input is working, with a proper screen display. puter monitors but it has to be done for also provided. A socket not normally You can elect to ignore the “Mode each and every screen resolution and found on monitors is 9-pin Mini D not found” message but if you do combination of horizontal and vertical to provide a serial interface between you will not be able to optimise the sync. With such a large screen and the computer and the monitor’s own convergence for your mode. Hence, fine dot pitch, picture imperfections September 1995  9 Fig.1: the schematic of the magnetic compensation cir­cuitry in the Philips Brilliance 21A monitor. It continuously compensates for any variations in external magnetic fields and ensures that optimum picture quality is maintained. that would go unnoticed on smaller monitors become critical, particu­larly at the higher screen resolutions. Magnetic field compensation All of the fine attention to detail in obtaining the best convergence, geo­ metry and uniformity of screen brightness are subject to a big hazard in the larger monitors. Simply rotating the monitor changes its orientation to the Earth’s magnetic field and thus the electronic beams scanning the picture are thrown off their optimised paths. This happens in all monitors but again, the larger the monitor, the worse the effect on the picture, especially as far as purity is concerned. Philips has been really clever here in introducing their innovative Cyber­screen Technology, a high fal­ utin’ name which embraces all the 21A’s digital control circuitry and, more par­ticularly, its magnetic field compensation. In essence, the 21A monitors the magnetic fields acting upon the monitor and then produces a compensating magnetic field so that the high convergence standard is constantly main­tained. The schematic of Fig.1 shows the general arrangement. A bridge of Hall Effect devices is used to monitor the magnetic fields and produce an offset voltage. This voltage is converted to 10  Silicon Chip a square wave by alternating current pulses fed to the inver­sion coil. The output square wave’s amplitude is proportional to the magnetic field strength. The square wave is AC coupled to the processing unit to remove the offset and amplified. The signal is then applied to the purity coils to correct the monitor’s conver­gence – a classic feedback circuit. The correction signal is also rectified to produce a DC voltage proportional to the magnetic field. This voltage is applied to the degauss circuit where any change in level triggers the degauss circuit. Hence, at any time, the Brilliance 21A may perform an automatic degauss which you see as a momentary picture distortion accompanied by the characteristic audible twitch from the degauss coils. The proof of the pudding While it is easy to be overwhelmed by the complexity of this monitor and its operating procedures, the proof is in the outstanding picture quality. The monitor was used mainly with a CAD program at a resolution of 1280 x 1024 pixels and the display showed excellent geometry, even brightness and good resolution. With my usual monitor (a 20-inch colour monitor with 0.31mm dot pitch), I need to zoom in frequently on large drawings, particu­larly when placing type; circles that appear round at the centre of the screen are not so when moved away from centre. This is not the case with the 21A. Type placement does not require the same level of zoom and circles are circles no matter where they are placed on the screen. As noted above, high resolution mode in one monitor is not the same as on another and this is where you really notice the picture quality of the Brilliance 21A –it is aptly named. A minor irritation is the delay that occurs when the reso­lution changes within a program. For example, if the program shells out to DOS, to perform a print command, then the monitor takes a noticeable time to find the correct resolution file and show a correctly scanned picture. This delay is longer than the switching time of the relays in a multi-sync monitor. As well as being ideal for desktop publishing and CAD pro­ grams, the Brilliance 21A would appear to be ideally suited to any program where colour accuracy is paramount such as in advertising production, textile and fashion design, and so on. At the time of writing, the Philips Brilliance 21A is priced at $5270 plus tax where applicable. Further information can be obtained from Philips Business Electronics, Technology Park, 3 Figtree Drive, Homebush, NSW 2140. Phone 1 800 658 086. SC